Separation technique provides rapid quantitative determination of cesium-137 in irradiated nuclear fuel

NASA Technical Reports Server (NTRS)

Ellenburg, E. J.; Mc Cown, J. J.

1967-01-01

Potassium cobalt ferrocyanide is used to determine cesium-137 activity in irradiated fuel samples. It preferentially removes cesium from an acid solution of the fuel material. The residue is filtered and analyzed with a gamma spectrometer.

METHOD FOR THE RECOVERY OF CESIUM VALUES

DOEpatents

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.

Method for removing cesium from a nuclear reactor coolant

DOEpatents

Colburn, R.P.

1983-08-10

A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium inventory thereof further into the carbon matrix while simultaneously redispersing a portion into the regeneration system for absorption at a reduced temperature by the secondary trap.

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

PubMed

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.

Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive 137Cs

PubMed Central

Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

2015-01-01

In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium (137Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of 137Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of 137Cs from contaminated water around nuclear plants and/or after nuclear accidents. PMID:26670798

Method for aqueous radioactive waste treatment

DOEpatents

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.

Method for aqueous radioactive waste treatment

DOEpatents

Bray, Lane A.; Burger, Leland L.

1994-01-01

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.

Precipitation-adsorption process for the decontamination of nuclear waste supernates

DOEpatents

Lee, Lien-Mow; Kilpatrick, Lester L.

1984-01-01

High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

Precipitation-adsorption process for the decontamination of nuclear waste supernates

DOEpatents

Lee, L.M.; Kilpatrick, L.L.

1982-05-19

High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

Preparation and use of tetra-alkyl cobalt dicarbollide for extraction of cesium and strontium into hydrocarbon solvents

DOEpatents

Miller, Rebecca L.; Pinkerton, Anthony B.; Abney, Kent D.; Kinkead, Scott A.

1997-01-01

Preparation and use of tetra-C-alkyl cobalt dicarbollide for extraction of cesium and strontium into hydrocarbon solvents. Tetra-C-alkyl derivatives of cobalt dicarbollide, Co(C.sub.2 R.sub.2 B.sub.9 H.sub.9).sub.2.sup.- (CoB.sub.2 R.sub.4.sup.- ; R=CH.sub.3 and C.sub.6 H.sub.13) are demonstrated to be significant cesium and strontium extractants from acidic and alkaline solutions into non-toxic organic solvent systems. Extractions using mesitylene and diethylbenzene are compared to those with nitrobenzene as the organic phase. CoB.sub.2 -hexyl.sub.4.sup.- in diethylbenzene shows improved selectivity (10.sup.4) for Cs over Na in acidic solution. In dilute alkaline solution, CoB.sub.2 -hexyl.sub.4.sup.- extracts Cs less efficiently, but more effectively removes Sr from higher base concentrations. A general synthesis of tetra-C-alkyl cobalt dicarbollides is described.

Preparation and use of tetra-alkyl cobalt dicarbollide for extraction of cesium and strontium into hydrocarbon solvents

DOEpatents

Miller, R.L.; Pinkerton, A.B.; Abney, K.D.; Kinkead, S.A.

1997-02-11

Preparation and use of tetra-C-alkyl cobalt dicarbollide for extraction of cesium and strontium into hydrocarbon solvents. Tetra-C-alkyl derivatives of cobalt dicarbollide, Co(C{sub 2}R{sub 2}B{sub 9}H{sub 9}){sub 2}{sup {minus}}(CoB{sub 2}R{sub 4}{sup {minus}}; R=CH{sub 3} and C{sub 6}H{sub 13}) are demonstrated to be significant cesium and strontium extractants from acidic and alkaline solutions into non-toxic organic solvent systems. Extractions using mesitylene and diethylbenzene are compared to those with nitrobenzene as the organic phase. CoB{sub 2}-hexyl{sub 4}{sup {minus}} in diethylbenzene shows improved selectivity (10{sup 4}) for Cs over Na in acidic solution. In dilute alkaline solution, CoB{sub 2}-hexyl{sub 4}{sup {minus}} extracts Cs less efficiently, but more effectively removes Sr from higher base concentrations. A general synthesis of tetra-C-alkyl cobalt dicarbollides is described. 6 figs.

SELECTIVE REMOVAL OF STRONTIUM AND CESIUM FROM SIMULATED WASTE SOLUTION WITH TITANATE ION EXCHANGERS IN A FILTER CARTRIDGE CONFIGURATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L.; Martin, K.; Hobbs, D.

2011-05-26

This report describes experimental results for the selective removal of strontium and cesium from simulated waste solutions using monosodium titanate (MST) and crystalline silicotitanate (CST)-laden filter cartridges. Four types of ion exchange cartridge media (CST and MST designed by both 3M and POROX{reg_sign}) were evaluated. In these proof-of-principle tests effective uptake of both Sr-85 and Cs-137 was observed. However, the experiments were not performed long enough to determine the saturation levels or breakthrough curve for each filter cartridge. POREX{reg_sign} MST cartridges, which by design were based on co-sintering of the active titanates with polyethylene particles, seem to perform as wellmore » as the 3M-designed MST cartridges (impregnated filter membrane design) in the uptake of strontium. At low salt simulant conditions (0.29 M Na{sup +}), the instantaneous decontamination factor (D{sub F}) for Sr-85 with the 3M-design MST cartridge measured 26, representing the removal of 96% of the Sr-85. On the other hand, the Sr-85 instantaneous D{sub F} with the POREX{reg_sign} design MST cartridge measured 40 or 98% removal of the Sr-85. Strontium removal with the 3M-design MST and CST cartridges placed in series filter arrangement produced an instantaneous decontamination factor of 41 or 97.6% removal compared to an instantaneous decontamination factor of 368 or 99.7% removal of the strontium with the POREX{reg_sign} MST and CST cartridge design placed in series. At high salt simulant conditions (5.6 M Na{sup +}), strontium removal with 3M-designed MST cartridge only and with 3M-designed MST and CST cartridges operated in a series configuration were identical. The instantaneous decontamination factor and the strontium removal efficiency, under the above configuration, averaged 8.6 and 88%, respectively. There were no POREX{reg_sign} cartridge experiments using the higher ionic strength simulant solution. At low salt simulant conditions, the uptake of Cs-137 with POREX{reg_sign} CST cartridge out performed the 3M-designed CST cartridges. The POREX{reg_sign} CST cartridge, with a Cs-137 instantaneous decontamination factor of 55 and a Cs-137 removal efficiency of 98% does meet the Cs-137 decontamination goals in the low salt simulant liquor. The Cs-137 removal with 3M-designed CST cartridge produced a decontamination factor of 2 or 49% removal efficiency. The Cs-137 performance graph for the 3M-designed CST cartridge showed an early cessation in the uptake of cesium-137. This behavior was not observed with the POREX{reg_sign} CST cartridges. No Cs-137 uptake tests were performed with the POREX{reg_sign} CST cartridges at high salt simulant conditions. The 3M-designed CST cartridges, with an instantaneous Cs-137 decontamination factor of less than 3 and a Cs-137 removal efficiency of less than 50% failed to meet the Cs-137 decontamination goals in both the low and high salt simulant liquors. This poor performance in the uptake of Cs-137 by the 3M CST cartridges may be attributed to fabrication flaws for the 3M-designed CST cartridges. The reduced number of CST membrane wraps per cartridge during the cartridge design phase, from 3-whole wraps to about 1.5, may have contributed to Cs-137 laden simulant channeling/by-pass which led to the poor performance in terms of Cs-137 sorption characteristics for the 3M designed CST cartridges. The grinding of CST ion exchange materials, to reduce the particle size distribution and thus enhance their easy incorporation into the filter membranes and the co-sintering of MST with polyethylene particles, did not adversely affect the sorption kinetics of both CST and MST in the uptake of Cs-137 and Sr-85, respectively. In general, the POREX{reg_sign} based cartridges showed more resistance to simulant flow through the filter cartridges as evidenced by higher pressure differences across the cartridges. Based on these findings they conclude that incorporating MST and CST sorbents into filter membranes represent a promising method for the semi-continuous removal of radioisotopes of strontium and cesium from waste solutions.« less

An Experimental Study of the Fluorescence Spectrum of Cesium Atoms in the Presence of a Buffer Gas

NASA Astrophysics Data System (ADS)

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.

The effect of temperature and radiation on the cesium adsorption ability of IONSIV/256 IE-910 and IONSIV/256 IE-911

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, K.B.

1999-12-08

This study examined the ion exchange capacity of crystalline silicotitanate in a simulated waste solution. The focus areas included the effect of temperature and radiation on cesium sorption capacity. The cesium is expected to be removed from high-level radioactive wastes using these ion exchange materials.

Mycoextraction of radiolabeled cesium and strontium by Pleurotus eryngii mycelia in the presence of alumina nanoparticles: Sorption and accumulation studies.

PubMed

Asztemborska, Monika; Jakubiak, Małgorzata; Rykaczewska, Magdalena; Bembenek, Marcin; Stęborowski, Romuald; Bystrzejewska-Piotrowska, Grażyna

2016-11-01

Widespread use of products based on nanomaterials results in the release of nanoparticles into the environment. Nanoparticles can be taken up by organisms, but they can also coexist with other substances such as radionuclides, thus affecting their uptake or toxicity. In contrast, the sorption capacity of nanoparticles is exploited in water purification. The aim of the study was to investigate: (i) bioaccumulation of cesium and strontium by Pleurotus eryngii mycelia in the presence of alumina nanoparticles (Al 2 O 3 NPs); and (ii) sorption of radionuclides on the surface of nanoparticles. For the experiments, living and dried mycelia were used to permit distinguishing between active uptake and passive sorption of the NPs by P. eryngii. The results are discussed from the perspective of the use of P. eryngii in the mycoextraction of radionuclides. The sorption capacity of Al 2 O 3 NPs and the accumulation by P. eryngii mycelia differ for the applied radioisotopes. The efficiency of Cs and Sr sorption by alumina nanoparticles is 20% and 40%, respectively. Mycelia of P. eryngii have the ability to accumulate 30% of both radioisotopes from the medium. More than 60% of strontium can be removed accumulated from water by P. eryngii mycelia in coexistence with Al 2 O 3 NPs, while the efficiency of cesium removal accumulation is negligible. It was found that alumina nanoparticles do not enhance uptake of radionuclides by P. eryngii mycelia; mycoextraction of radionuclides by mycelia and sorption by Al 2 O 3 NPs are concurrent processes. There was no difference between live or dried mycelia uptake. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of Cesium From Acidic Radioactive Tank Waste Using IONSIV IE-911 (CST)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mann, Nicholas Robert; Todd, Terry Allen

2004-10-01

IONSIV IE-911, or the engineered form of crystalline silicotitanate (CST), manufactured by UOP Molecular Sieves, has been evaluated for the removal of cesium from Idaho National Engineering and Environmental Laboratory (INEEL) acidic radioactive tank waste. A series of batch contacts and column tests were performed by using three separate batches of CST. Batch contacts were performed to evaluate the concentration effects of nitric acid, sodium, and potassium ions on cesium sorption. Additional batch tests were performed to determine if americium, mercury, and plutonium would sorb onto IONSIV IE-911. An equilibrium isotherm was generated by using a concentrated tank waste simulant.more » Column tests using a 1.5 cm 3 column and flow rates of 3, 5, 10, 20, and 30 bed volumes (BV)/hr were performed to elucidate dynamic cesium sorption capacities and sorption kinetics. Additional experiments investigated the effect of CST batch and pretreatment on cesium sorption. The thermal stability of IONSIV IE-911 was evaluated by performing thermal gravimetric analysis/differential thermal analysis. Overall, IONSIV IE-911 was shown to be effective for cesium sorption from complex, highly acidic solutions; however, sorbent stability in these solutions may have a deleterious effect on cesium sorption.« less

Research on the treatment of liquid waste containing cesium by an adsorption-microfiltration process with potassium zinc hexacyanoferrate.

PubMed

Zhang, Chang-Ping; Gu, Ping; Zhao, Jun; Zhang, Dong; Deng, Yue

2009-08-15

The removal of cesium from an aqueous solution by an adsorption-microfiltration (AMF) process was investigated in jar tests and lab-scale tests. The adsorbent was K(2)Zn(3)[Fe(CN)(6)](2). The obtained cesium data in the jar test fit a Freundlich-type isotherm well. In the lab-scale test, the mean cesium concentration of the raw water and the effluent were 106.87 microg/L and 0.59 microg/L, respectively, the mean removal of cesium was 99.44%, and the mean decontamination factors (DF) and concentration factors (CF) were 208 and 539, respectively. The removal of cesium in the lab-scale test was better than that in the jar test because the old adsorbents remaining in the reactor still had adsorption capacity with the premise of no significant desorption being observed, and the continuous renewal of the adsorbent surface improved the adsorption capacity of the adsorbent. Some of the suspended solids were deposited on the bottom of the reactor, which would affect the mixing of adsorbents with the raw water and the renewing of the adsorbent surface. Membrane fouling was the main physical fouling mechanism, and the cake layer was the main filtration resistance. Specific flux (SF) decreased step by step during the whole period of operation due to membrane fouling and concentration polarization. The quality of the effluent was good and the turbidity remained lower than 0.1NTU, and the toxic anion, CN(-), could not be detected because of its low concentration, this indicated that the effluent was safe. The AMF process was feasible for practical application in the treatment of liquid waste containing cesium.

Evaluation of a method for removing cesium and reducing the volume of leaf litter from broad-leaved trees contaminated by the Fukushima Daiichi nuclear accident during the Great East Japan Earthquake.

PubMed

Harada, Shigeki; Yanagisawa, Mitsunori

2017-04-01

The town of Marumori in southern Miyagi Prefecture borders on Fukushima Prefecture, and following the accident at the Fukushima Daiichi nuclear power plant, there were concerns about cesium deposition in forested areas. One of the authors of this paper has continually surveyed leaf litter from the forested areas. As leaf litter may be a source of cesium contamination from the forest to downstream areas, we considered a simplified version of wet oxidation, a method previously presented by one of the authors of this study, as a technology to reduce leaf litter weight and cesium concentration, separating radioactive nuclides from non-radioactive ones, in leaf litter. We tested our method in three experiments. Experiment 1 used new leaf litter (232 Bq/kg) from the surface of a small stream at the forest edge nearby an area with air dose level higher than the national standard threshold of 0.23 μSv/h for the implementation of governmental decontamination works. Experiment 2 applied wet oxidation to older leaf litter (705 Bq/kg) harvested from a pasture nearby the stream mentioned above. We also used the same leaf litter in experiment 3 for a cesium release tests using pure water. In experiment 1 and 2 we treated leaf litter with a sodium hypochlorite solution, optimizing sodium hypochlorite concentration and reaction temperature. We measured a 50-60% decrease in the leaf litter weight and a 60% decrease in the cesium concentration. Moreover, we also measured the amount of cesium washout. The cesium budget of experiment 1 showed no cesium gasification (wet oxidation avoids airborne cesium as this element is prone to be volatile at 600 °C), and that high sodium hypochlorite concentration and high temperature had a strong positive effect on leaf litter volume reduction and cesium decontamination. Experiment 2 confirmed the reproducibility of these results in leaves with different cesium concentration and harvested in different conditions. We could also explain the mechanism behind leaf litter weight and cesium concentration reduction. Experiment 3 helped us to investigate the effects of the matter present on the surface of the water and the contribution of water soluble cesium. Concurrent experiments on changes in leaf litter chemical composition confirmed that our modified wet oxidation method had an effect on the removal of acid-insoluble lignin. Removal of lignin, a refractory component, might allow for a better utilization of the residue left after implementation of the proposed simplified wet oxidation. Thus, real wastes could be smaller than the residues. Together with the observed smaller cesium concentration in the residue, the proposed method in this study is expected to contribute to mitigate the risk due to the fallen leaves containing cesium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption of cesium ion by marine actinobacterium Nocardiopsis sp. 13H and their extracellular polymeric substances (EPS) role in bioremediation.

PubMed

Sivaperumal, Pitchiah; Kamala, Kannan; Rajaram, Rajendran

2018-02-01

This paper evaluates the cesium adsorption of marine actinobacterium Nocardiposis sp. 13H strain isolated from nuclear power plant sites in India. It could remove 88.6 ± 0.72% of Cs + from test solution containing 10 mM CsCl 2 . The biosorption of Cs + with different environmental factors such as pH, temperature, and time interval is also determined. Scanning electron microscopy coupled with energy dispersive spectroscopy (EDS) confirmed the Cs + adsorption by Nocardiopsis sp. 13H. Most of the bound cesium was found to be associated extracellular polymeric substances (EPS) suggesting its interaction with the surface active groups. The main component of the EPS was carbohydrate followed by protein and nucleic acid. Further, Fourier transform infrared (FTIR) spectroscopy suggested the carboxyl, hydroxyl, and amide groups on the strain cell surface were likely to be involved in Cs + adsorption. Results from this study show Nocardiopsis sp. 13H microorganism could be useful in exploring the biosorption of radioisotope pollution and developing efficient and eco-friendly biosorbent for environmental cleanup.

A Reliable Hybrid Adsorbent for Efficient Radioactive Cesium Accumulation from Contaminated Wastewater

PubMed Central

Awual, Md. Rabiul; Yaita, Tsuyoshi; Miyazaki, Yuji; Matsumura, Daiju; Shiwaku, Hideaki; Taguchi, Tomitsugu

2016-01-01

Cesium (Cs) removal from nuclear liquid wastewater has become an emerging issue for safeguarding public health after the accident at the Fukushima Daiichi Nuclear Power Plant. A novel macrocyclic ligand of o-benzo-p-xylyl-22-crown-6-ether (OBPX22C6) was developed and successfully immobilized onto mesoporous silica for the preparation of hybrid adsorbent. The benzene ring π electron is the part of crown ether of OBPX22C6 for easy orientation of the macrocyclic compound for making the π electron donation with Cs complexation. The potential and feasibility of the hybrid adsorbent as being Cs selective was evaluated in terms of sensitivity, selectivity and reusability. The results clarified that the Cs removal process was rapid and reached saturation within a short time. Considering the effect of competitive ions, sodium (Na) did not markedly affect the Cs adsorption whereas potassium (K) was slightly affected due to the similar ionic radii. However, the oxygen in long ethylene glycol chain in OBPX22C6 was expected to show strong coordination, including Cs-π interaction with Cs even in the presence of the high amount of K and Na. Due to its high selectivity and reusability, significant volume reduction is expected as this promising hybrid adsorbent is used for Cs removal in Fukushima wastewater. PMID:26818070

A Reliable Hybrid Adsorbent for Efficient Radioactive Cesium Accumulation from Contaminated Wastewater.

PubMed

Awual, Md Rabiul; Yaita, Tsuyoshi; Miyazaki, Yuji; Matsumura, Daiju; Shiwaku, Hideaki; Taguchi, Tomitsugu

2016-01-28

Cesium (Cs) removal from nuclear liquid wastewater has become an emerging issue for safeguarding public health after the accident at the Fukushima Daiichi Nuclear Power Plant. A novel macrocyclic ligand of o-benzo-p-xylyl-22-crown-6-ether (OBPX22C6) was developed and successfully immobilized onto mesoporous silica for the preparation of hybrid adsorbent. The benzene ring π electron is the part of crown ether of OBPX22C6 for easy orientation of the macrocyclic compound for making the π electron donation with Cs complexation. The potential and feasibility of the hybrid adsorbent as being Cs selective was evaluated in terms of sensitivity, selectivity and reusability. The results clarified that the Cs removal process was rapid and reached saturation within a short time. Considering the effect of competitive ions, sodium (Na) did not markedly affect the Cs adsorption whereas potassium (K) was slightly affected due to the similar ionic radii. However, the oxygen in long ethylene glycol chain in OBPX22C6 was expected to show strong coordination, including Cs-π interaction with Cs even in the presence of the high amount of K and Na. Due to its high selectivity and reusability, significant volume reduction is expected as this promising hybrid adsorbent is used for Cs removal in Fukushima wastewater.

Preliminary Evaluation of Cesium Distribution for Wet Sieving Process Planned for Soil Decontamination in Japan - 13104

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enokida, Y.; Tanada, Y.; Hirabayashi, D.

2013-07-01

For the purpose of decontaminating radioactive cesium from a huge amount of soil, which has been estimated to be 1.2x10{sup 8} m{sup 3} by excavating to a 5-cm depth from the surface of Fukushima Prefecture where a severe nuclear accident occurred at TEPCO's power generating site and has emitted a significant amount of radioactive materials, mainly radioactive cesium, a wet sieving process was selected as one of effective methods available in Japan. Some private companies have demonstrated this process for soil treatment in the Fukushima area by testing at their plants. The results were very promising, and a full-fledged applicationmore » is expected to follow. In the present study, we spiked several aqueous samples containing soil collected from an industrial wet sieving plant located near our university for the recycling of construction wastes with non-radioactive cesium hydroxide. The present study provides scientific data concerning the effectiveness in volume reduction of the contaminated soil by a wet sieving process as well as the cesium distribution between the liquid phase and clay minerals for each sub-process of the full-scale one, but a simulating plant equipped with a process of coagulating sedimentation and operational safety fundamentals for the plant. Especially for the latter aspect, the study showed that clay minerals of submicron size strongly bind a high content of cesium, which was only slightly removed by coagulation with natural sedimentation (1 G) nor centrifugal sedimentation (3,700 G) and some of the cesium may be transferred to the effluent or recycled water. By applying ultracentrifugation (257,000 G), most of submicron clay minerals containing cesium was removed, and the cesium amount which might be transferred to the effluent or recycled water, could be reduced to less than 2.3 % of the original design by the addition of a cesium barrier consisting of ultracentrifugation or a hollow fiber membrane. (authors)« less

Phenolic cation exchange resin material for recovery of cesium and strontium

DOEpatents

Ebra, Martha A.; Wallace, Richard M.

1983-01-01

A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear waste solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs.sup.+ and Sr.sup.2+ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

Phenolic cation-exchange resin material for recovery of cesium and strontium. [Patent application

DOEpatents

Ebra, M.A.; Wallace, R.M.

1982-05-05

A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear wate solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs/sup +/ and Sr/sup 2 +/ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

Cesium separation from contaminated milk using magnetic particles containing crystalline silicotitantes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nunez, L.; Kaminski, M.; Chemical Engineering

2000-11-01

The Chernobyl nuclear reactor disaster in 1986 contaminated vast regions of prime grazing land. Subsequently, milk produced in the region has been contaminated with small amounts of the long-lived fission product cesium-137, and the Ukraine is seeking to deploy a simple separation process that will remove the Cs and preserve the nutritional value of the milk. Tiny magnetic particles containing crystalline silicotitanates (CST) have been manufactured and tested to this end. The results show that partitioning efficiency is optimized with low ratios of particle mass to volume. To achieve 90% Cs decontamination in a single-stage process, <3 g of magneticmore » CST per l milk is sufficient with a 30-min mixing time. A two-stage process would utilize <0.4 g/l per stage. The modeling of the magnetic CST system described herein can be achieved rather simply which is important for deployment in the affected Ukraine region.« less

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 Experiement

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2005-04-01

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 CSTmore » 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.« less

High-efficiency, low-temperature cesium diodes with lanthanum-hexaboride electrodes

NASA Technical Reports Server (NTRS)

Morris, J. F.

1974-01-01

Lanthanum hexaboride electrodes in 1700 K cesium diodes may triple power outputs compared with those demonstrated for nuclear thermionic space applications. Still greater relative gains seem possible for emitters below 1700 K. Further improvements in cesium diode performance should result from the lower collector temperatures allowed for earth and low power space duties. Decreased temperatures will lessen thermal transport losses that attend thermionic conversion mechanisms. Such advantages will add to those from collector Carnot and electrode effects. If plasma ignition difficulties impede diode temperature reductions, recycling small fractions of the output power could provide ionization. So high efficiency, low temperature cesium diodes with lanthanum hexaboride electrodes appear feasible.

Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium.

PubMed

Goñi, S; Guerrero, A; Lorenzo, M P

2006-10-11

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 degrees 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).

Transfer of radio-cesium from forest soil to woodchips using fungal activities

NASA Astrophysics Data System (ADS)

Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

2014-05-01

Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be removed from forests with fungal bodies. We covered forest floor using wood chips, and observed Cs accumulation, and found that up to 50% of soil radio-cesium was transferred from soil to wood chips after 6-month of field incubation. Therefore this method is effective to decontaminate forest using ecological process. Kaneko N, Huang Y, Nakamori T, Tanaka Y, Nonaka M. Radio-cesium accumulation during decomposition of leaf litter in a deciduous forest after the Fukushima NPP accident. Geophysical Research Abstracts. 2013;15(EGU2013):7809.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2005-04-01

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 ofmore » 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.« less

Cesium-specific phenolic ion exchange resin

DOEpatents

Bibler, J.P.; Wallace, R.M.

1995-08-15

A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio. 2 figs.

Cesium-specific phenolic ion exchange resin

DOEpatents

Bibler, Jane P.; Wallace, Richard M.

1995-01-01

A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio.

Removal of cesium from simulated liquid waste with countercurrent two-stage adsorption followed by microfiltration.

PubMed

Han, Fei; Zhang, Guang-Hui; Gu, Ping

2012-07-30

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 101.3μg/L, the dosage of CuFC was 40mg/L and the adsorption time was 20min. 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 98.75μg/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. Copyright © 2012 Elsevier B.V. All rights reserved.

An Improvement to Low-Level Radioactive Waste Vitrification Processes.

DTIC Science & Technology

1986-05-01

waste stream. 3 9 Sodium and Potassium tetraphenyl borates are both cited in the literature as having high cesium selectivity. 23󈧝󈧫 The thermal... Ferrate (II) Impregnated Zeolite for Cesium Removal from Radioactive Waste," Nuc. Tech., 58, p.242, ANS, La Grange Park, Illinois, (1982T. 29. F.V

Ion Exchange Modeling of Crystalline Silicotitanate (IONSIV(R) IE-911) Column for Cesium Removal from Argentine Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hang, T.

2003-07-16

The U.S. Department of Energy (DOE) and the Nuclear Energy Commission of Argentina (CNEA) have a collaborative project to separate cesium/strontium from waste resulting from the production of Mo-99. The Pacific Northwest National Laboratory (PNNL) is assisting DOE on this joint project by providing technical guidance to CNEA scientists. As part of the collaboration, PNNL staff works with staff at the Savannah River Technology Center (SRTC) to run the VERSE-LC model for removal of cesium from the Mo-99 waste using the crystalline silicotitanate (CST) material (IONSIV(R) IE-911, UOP LLC, DesPlaines, IL) based on technical data provided by CNEA. This reportmore » discusses the VERSE-LC ion-exchange-column model and the predicted results of CNEA test cases.« less

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

PubMed

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.

A novel role for methyl cysteinate, a cysteine derivative, in cesium accumulation in Arabidopsis thaliana

PubMed Central

Adams, Eri; Miyazaki, Takae; Hayaishi-Satoh, Aya; Han, Minwoo; Kusano, Miyako; Khandelia, Himanshu; Saito, Kazuki; Shin, Ryoung

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 were investigated. Through chemical library screening, 14 chemicals were isolated as ‘cesium accumulators’ in Arabidopsis thaliana. Of those, methyl cysteinate, a derivative of cysteine, was found to function within the plant to accumulate externally supplemented cesium. Moreover, metabolite profiling demonstrated that cesium treatment increased cysteine levels in Arabidopsis. The cesium accumulation effect was not observed for other cysteine derivatives or amino acids on the cysteine metabolic pathway tested. Our results suggest that methyl cysteinate, potentially metabolised from cysteine, binds with cesium on the surface of the roots or inside plant cells and improve phytoaccumulation. PMID:28230101

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 havemore » 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. Application of RF for cesium removal in the Hanford WTP does not involve in-riser columns but does utilize the resin in large scale column configurations in a waste treatment facility. The basic conceptual design for SCIX involves the dissolution of saltcake in SRS Tanks 1-3 to give approximately 6 M sodium solutions and the treatment of these solutions for cesium removal using one or two columns supported within a high level waste tank. Prior to ion exchange treatment, the solutions will be filtered for removal of entrained solids. In addition to Tanks 1-3, solutions in two other tanks (37 and 41) will require treatment for cesium removal in the SCIX unit. The previous SCIX design (McCabe, 2005) utilized CST for cesium removal with downflow supernate processing and included a CST grinder following cesium loading. Grinding of CST was necessary to make the cesium-loaded material suitable for vitrification in the SRS Defense Waste Processing Facility (DWPF). Because RF resin is elutable (and reusable) and processing requires conversion between sodium and hydrogen forms using caustic and acidic solutions more liquid processing steps are involved. The WTP baseline process involves a series of caustic and acidic solutions (downflow processing) with water washes between pH transitions across neutral. In addition, due to resin swelling during conversion from hydrogen to sodium form an upflow caustic regeneration step is required. Presumably, one of these basic processes (or some variation) will be utilized for MSP for the appropriate ion exchange technology selected. CST processing involves two primary waste products: loaded CST and decontaminated salt solution (DSS). RF processing involves three primary waste products: spent RF resin, DSS, and acidic cesium eluate, although the resin is reusable and typically does not require replacement until completion of multiple treatment cycles. CST processing requires grinding of the ion exchange media, handling of solids with high cesium loading, and handling of liquid wash and conditioning solutions. RF processing requires handling and evaporation of cesium eluates, disposal of spent organic resin, and handling of the various liquid wash and regenerate solutions used. In both cases, the DSS will be immobilized in a low activity waste form. It appears that both technologies are mature, well studied, and generally suitable for this application. Technology selection will likely be based on downstream impacts or preferences between the various processing options for the two materials rather than on some unacceptable performance property identified for one material. As a result, the following detailed technical review and summary of the two technologies should be useful to assist in technology selection for SCIX.« less

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

DOEpatents

Abney, Kent D.; Kinkead, Scott A.; Mason, Caroline F. V.; Rais, Jiri

1997-01-01

Preparation and use of 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.

Fluoro-alcohol phase modifiers and process for cesium solvent extraction

DOEpatents

Bonnesen, Peter V.; Moyer, Bruce A.; Sachleben, Richard A.

2003-05-20

The invention relates to a class of phenoxy fluoro-alcohols, their preparation, and their use as phase modifiers and solvating agents in a solvent composition for the extraction of cesium from alkaline solutions. These phenoxy fluoro-alcohols comply with the formula: ##STR1## in which n=2 to 4; X represents a hydrogen or a fluorine atom, and R.sup.2 -R.sup.6 are hydrogen or alkyl substituents. These phenoxy fluoro-alcohol phase modifiers are a necessary component to a robust solvent composition and process useful for the removal of radioactive cesium from alkaline nuclear waste streams. The fluoro-alcohols can also be used in solvents designed to extract other cesium from acidic or neutral solutions.

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

DOEpatents

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

1997-09-09

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.

The Effect of Carbonate, Oxalate and Peroxide on the Cesium Loading of Ionsiv IE-910 and IE-911

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fondeur, F.F.

2000-12-19

The Savannah River Site (SRS) continues to examine three processes for the removal of radiocesium from high-level waste. One option involves the use of crystalline silicotitanate (CST) as a non-elutable ion exchange medium. The process uses CST in its engineered form - IONSIV IE-911 made by UOP, LLC. - in a column to contact the liquid waste. Cesium exchanges with sodium ions residing inside the CST particles. The design disposes of the cesium-loaded CST by vitrification within the Defense Waste Processing Facility.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry

NASA Astrophysics Data System (ADS)

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.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry

PubMed Central

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-01-01

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. PMID:25192495

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry.

PubMed

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-09-05

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.

High efficiency thermionic converter studies

NASA Technical Reports Server (NTRS)

Huffman, F. N.; Sommer, A. H.; Balestra, C. L.; Briere, T. R.; Lieb, D.; Oettinger, P. E.; Goodale, D. B.

1977-01-01

Research in thermionic energy conversion technology is reported. The objectives were to produce converters suitable for use in out of core space reactors, radioisotope generators, and solar satellites. The development of emitter electrodes that operate at low cesium pressure, stable low work function collector electrodes, and more efficient means of space charge neutralization were investigated to improve thermionic converter performance. Potential improvements in collector properties were noted with evaporated thin film barium oxide coatings. Experiments with cesium carbonate suggest this substance may provide optimum combinations of cesium and oxygen for thermionic conversion.

Use of charcoals and broiler litter biochar for removal of radioactive cesium (Cs-134 plus Cs-137) from contaminated water

USDA-ARS?s Scientific Manuscript database

Various charcoals (used in food processing and water treatment) and broiler litter biochar were examined for ability to adsorb water-soluble low-level radioactive cesium (ca. 200-250 Bq/kg) extracted from contaminated wheat bran. Among the materials tested, steam activated broiler litter biochar was...

Removal of radioactive cesium (134Cs plus 137Cs) from low-level contaminated water by charcoal and broiler litter biochar

USDA-ARS?s Scientific Manuscript database

Various charcoals (used in food processing and water treatment) and broiler litter biochar were examined for ability to adsorb water-soluble low-level radioactive cesium (ca. 200-250 Bq/kg) extracted from contaminated wheat bran. Among the materials tested, steam activated broiler litter biochar was...

A Simple and Rapid Method for Reducing Radiocesium Concentrations in Wild Mushrooms ( Cantharellus and Boletus ) in the Course of Cooking.

PubMed

Steinhauser, Georg; Steinhauser, Veronika

2016-11-01

Many species of mushrooms are known accumulators of radioactive cesium ( 137 Cs and 134 Cs). Even years and decades after major nuclear accidents, especially those at Chernobyl and Fukushima, mushrooms exhibit high concentrations of these radionuclides. We investigated a simple method for reducing the activity of radiocesium in wild mushrooms (chanterelles, Cantharellus cibarius ; and boleti, Boletus edulis ) during cooking. The juice generated while cooking mushrooms contains a relatively high fraction of the total cesium. The amount of juice can be increased by washing the mushrooms with water prior to cooking. By removing the juice, up to 29% of the radiocesium can be easily removed from chanterelles. Because boleti have a lower affinity for cesium, activity levels were lower in boleti than in chanterelles. The fraction of radiocesium in the juice was lower in boleti than in chanterelles.

An Inorganic Microsphere Composite for the Selective Removal of Cesium 137 from Acidic Nuclear Waste Solutions - Parts 1 and 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

T. J. Tranter; T. A. Vereschchagina; V. Utgikar

2009-03-01

A new inorganic ion exchange composite for removing radioactive cesium from acidic waste streams has been developed. The new material consists of ammonium molybdophosphate, (NH4)3P(Mo3O10)4•3H2O (AMP), synthesized within hollow aluminosilicate microspheres (AMP-C), which are produced as a by-product from coal combustion. The selective cesium exchange capacity of this inorganic composite was evaluated in bench-scale column tests using simulated sodium bearing waste solution as a surrogate for the acidic tank waste currently stored at the Idaho National Laboratory (INL). Total cesium loading on the columns at saturation agreed very well with equilibrium values predicted from isotherm experiments performed previously. A numericalmore » algorithm for solving the governing partial differential equations (PDE) for cesium uptake was developed using the intraparticle mass transfer coefficient obtained from previous batch kinetic experiments. Solutions to the governing equations were generated to obtain the cesium concentration at the column effluent as a function of throughput volume using the same conditions as those used for the actual column experiments. The numerical solutions of the PDE fit the column break through data quite well for all the experimental conditions in the study. The model should therefore provide a reliable prediction of column performance at larger scales. A new inorganic ion exchange composite consisting of ammonium molybdophosphate, (NH4)3P(Mo3O10)4•3H2O (AMP), synthesized within hollow aluminosilicate microspheres (AMP-C) has been developed. Two different batches of the sorbent were produced resulting in 20% and 25% AMP loading for two and three loading cycles, respectively. The selective cesium exchange capacity of this inorganic composite was evaluated using simulated sodium bearing waste solution as a surrogate for the acidic tank waste currently stored at the Idaho National Laboratory (INL). Equilibrium isotherms obtained from these experiments were very favorable for cesium uptake and indicated maximum cesium loading of approximately 9 % by weight of dry AMP. Batch kinetic experiments were also performed to obtain the necessary data to estimate the effective diffusion coefficient for cesium in the sorbent particle. These experiments resulted in effective intraparticle cesium diffusivity coefficients of 4.99 x 10-8 cm2/min and 4.72 x 10-8 cm2/min for the 20% and 25 % AMP-C material, respectively.« less

Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric.

PubMed

Bondar, Yuliia; Kuzenko, Svetlana; Han, Do-Hung; Cho, Hyun-Kug

2014-01-01

A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions.

Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric

PubMed Central

2014-01-01

A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions. PMID:24725367

MODELING OF ION-EXCHANGE FOR CESIUM REMOVAL FROM DISSOLVED SALTCAKE IN SRS TANKS 1-3, 37 AND 41

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, F

2007-08-15

This report presents an evaluation of the expected performance of engineered Crystalline Silicotitanate (CST) and spherical Resorcinol-Formaldehyde (RF) ion exchange resin for the removal of cesium from dissolved saltcake in SRS Tanks 1-3, 37 and 41. The application presented in this report reflects the expected behavior of engineered CST IE-911 and spherical RF resin manufactured at the intermediate-scale (approximately 100 gallon batch size; batch 5E-370/641). It is generally believed that scale-up to production-scale in RF resin manufacturing will result in similarly behaving resin batches whose chemical selectivity is unaffected while total capacity per gram of resin may vary. As such,more » the predictions provided within this report should provide reasonable estimates of production-scale column performance. Two versions of the RF cesium isotherm were used. The older version provides a conservative estimate of the resin capacity while the newer version more accurately fits the most recent experimental data.« less

Thermal Analysis for Ion-Exchange Column System

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 weremore » 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.« less

Record fifth-harmonic-generation efficiency producing 211 nm, joule-level pulses using cesium lithium borate

DOE PAGES

Begishev, I. A.; Bromage, J.; Yang, S. T.; ...

2018-05-16

The fifth harmonic of a pulsed Nd:YLF laser has been realized in a cascade of nonlinear crystals with a record efficiency of 30%. Cesium lithium borate is used in a Type-I configuration for sum-frequency mixing of 1053 nm and 266 nm, producing 211-nm pulses. Flattopped beam profiles and pulse shapes optimize efficiency. Furthermore, energies of the fifth harmonic up to 335 mJ in 2.4 ns pulses were demonstrated.

Record fifth-harmonic-generation efficiency producing 211  nm, joule-level pulses using cesium lithium borate

DOE PAGES

Begishev, I. A.; Bromage, J.; Yang, S. T.; ...

2018-01-01

The fifth harmonic of a pulsed Nd:YLF laser has been realized in a cascade of nonlinear crystals with a record efficiency of 30%. Cesium lithium borate is used in a Type-I configuration for sum-frequency mixing of 1053 nm and 266 nm, producing 211-nm pulses. Flattopped beam profiles and pulse shapes optimize efficiency. Energies of the fifth harmonic up to 335 mJ in 2.4 ns pulses were demonstrated.

Record fifth-harmonic-generation efficiency producing 211 nm, joule-level pulses using cesium lithium borate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Begishev, I. A.; Bromage, J.; Yang, S. T.

The fifth harmonic of a pulsed Nd:YLF laser has been realized in a cascade of nonlinear crystals with a record efficiency of 30%. Cesium lithium borate is used in a Type-I configuration for sum-frequency mixing of 1053 nm and 266 nm, producing 211-nm pulses. Flattopped beam profiles and pulse shapes optimize efficiency. Furthermore, energies of the fifth harmonic up to 335 mJ in 2.4 ns pulses were demonstrated.

Calixarene crown ether solvent composition and use thereof for extraction of cesium from alkaline waste solutions

DOEpatents

Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.; Presley, Derek J.

2001-01-01

A solvent composition and corresponding method for extracting cesium (Cs) from aqueous neutral and alkaline solutions containing Cs and perhaps other competing metal ions is described. The method entails contacting an aqueous Cs-containing solution with a solvent consisting of a specific class of lipophilic calix[4]arene-crown ether extractants dissolved in a hydrocarbon-based diluent containing a specific class of alkyl-aromatic ether alcohols as modifiers. The cesium values are subsequently recovered from the extractant, and the solvent subsequently recycled, by contacting the Cs-containing organic solution with an aqueous stripping solution. This combined extraction and stripping method is especially useful as a process for removal of the radionuclide cesium-137 from highly alkaline waste solutions which are also very concentrated in sodium and potassium. No pre-treatment of the waste solution is necessary, and the cesium can be recovered using a safe and inexpensive stripping process using water, dilute (millimolar) acid solutions, or dilute (millimolar) salt solutions. An important application for this invention would be treatment of alkaline nuclear tank wastes. Alternatively, the invention could be applied to decontamination of acidic reprocessing wastes containing cesium-137.

ETV REPORT: REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING WATER — PALL/KINETICO PUREFECTA DRINKING WATER TREATMENT SYSTEM

EPA Science Inventory

The Pall/Kinetico Purefecta™ POU drinking water treatment system was tested for removal of aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury, mevinphos, oxamyl, strontium, and strychnine. The Purefecta™ employs several compon...

Removal of radioactive iodine and cesium in water purification processes after an explosion at a nuclear power plant due to the Great East Japan Earthquake.

PubMed

Kosaka, Koji; Asami, Mari; Kobashigawa, Naoya; Ohkubo, Keiko; Terada, Hiroshi; Kishida, Naohiro; Akiba, Michihiro

2012-09-15

The presence of radionuclides at five water purification plants was investigated after an explosion at a nuclear power plant hit by the Great East Japan Earthquake on 11 March 2011. Radioactive iodine (¹³¹I) and cesium (¹³⁴Cs and ¹³⁷Cs) were detected in raw water in Fukushima and neighboring prefectures. ¹³¹I was not removed by coagulation-flocculation-sedimentation. ¹³¹I was removed by granular activated carbon (GAC) and powdered activated carbon (PAC) at a level of about 30%-40%, although ¹³¹I was not removed in some cases. This was also confirmed by laboratory-scale experiments using PAC. The removal percentages of ¹³¹I in river and pond waters by 25 mg dry/L of PAC increased from 36% to 59% and from 41% to 48%, respectively, with chlorine dosing before PAC. ¹³⁴Cs and ¹³⁷Cs were effectively removed by coagulation at both a water purification plant and in laboratory-scale experiments when turbidity was relatively high. In contrast, ¹³⁴Cs and ¹³⁷Cs in pond water with low turbidity were not removed by coagulation. This was because ¹³⁴Cs and ¹³⁷Cs in river water were present mainly in particulate form, while in pond water they were present mainly as cesium ions (¹³⁴Cs+ and ¹³⁷Cs+). However, the removal of ¹³⁴Cs and ¹³⁷Cs in pond water by coagulation increased markedly when ¹³⁴Cs and ¹³⁷Cs were mixed with sediment 24 h before coagulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Test Report for Cesium and Solids Removal from an 11.5L Composite of Archived Hanford Double Shell Tank Supernate for Off-Site Disposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doll, Stephanie R.; Cooke, Gary A.

The 222-S Laboratory blended supernate waste from Hanford Tanks 241-AN-101, 241-AN- 106, 241-AP-105, 241-AP-106, 241-AP-107, and 241-AY-101 from the hot cell archive to create a bulk composite. The composite was blended with 600 mL 19.4 M NaOH, which brought the total volume to approximately 11.5 L (3 gal). The composite was filtered to remove solids and passed through spherical resorcinol-formaldehyde ion-exchange resin columns to remove cesium. The composite masses were tracked as a treatability study. Samples collected before, during, and after the ion-exchange process were characterized for a full suite of analytes (inorganic, organic, and radionuclides) to aid in themore » classification of the waste for shipping, receiving, treatment, and disposal determinations.« less

Test Report for Cesium and Solids Removal from an 11.5L Composite of Archived Hanford Double Shell Tank Supernate for Off-Site Disposal.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doll, S. R.; Cooke, G. A.

The 222-S Laboratory blended supernate waste from Hanford Tanks 241-AN-101, 241-AN- 106, 241-AP-105, 241-AP-106, 241-AP-107, and 241-AY-101 from the hot cell archive to create a bulk composite. The composite was blended with 600 mL 19.4 M NaOH, which brought the total volume to approximately 11.5 L (3 gal). The composite was filtered to remove solids and passed through spherical resorcinol-formaldehyde ion-exchange resin columns to remove cesium. The composite masses were tracked as a treatability study. Samples collected before, during, and after the ion exchange process were characterized for a full suite of analytes (inorganic, organic, and radionuclides) to aid inmore » the classification of the waste for shipping, receiving, treatment, and disposal determinations.« less

Experimental investigation on a diode-pumped cesium-vapor laser stably operated at continuous-wave and pulse regime.

PubMed

Chen, Fei; Xu, Dongdong; Gao, Fei; Zheng, Changbin; Zhang, Kuo; He, Yang; Wang, Chunrui; Guo, Jin

2015-05-04

Employing a fiber-coupled diode-laser with a center wavelength of 852.25 nm and a line width of 0.17 nm, experimental investigation on diode-end-pumped cesium (Cs) vapor laser stably operated at continuous-wave (CW) and pulse regime is carried out. A 5 mm long cesium vapor cell filled with 60 kPa helium and 20 kPa ethane is used as laser medium. Using an output coupler with reflectivity of 48.79%, 1.26 W 894.57 nm CW laser is obtained at an incident pump power of 4.76 W, corresponding an optical-optical efficiency of 26.8% and a slope-efficiency of 28.8%, respectively. The threshold temperature is 67.5 °C. Stable pulsed cesium laser with a maximum average output power of 2.6 W is obtained at a repetition rate of 76 Hz, and the pulse repetition rate can be extend to 1 kHz with a pulse width of 18 μs.

FAST NEUTRON DOSIMETER FOR HIGH TEMPERATURE OPERATION BY MEASUREMENT OF THE AMOUNT OF CESIUM 137 FORMED FROM A THORIUM WIRE

DOEpatents

McCune, D.A.

1964-03-17

A method and device for measurement of integrated fast neutron flux in the presence of a large thermal neutron field are described. The device comprises a thorium wire surrounded by a thermal neutron attenuator that is, in turn, enclosed by heat-resistant material. The method consists of irradiating the device in a neutron field whereby neutrons with energies in excess of 1.1 Mev cause fast fissions in the thorium, then removing the thorium wire, separating the cesium-137 fission product by chemical means from the thorium, and finally counting the radioactivity of the cesium to determine the number of fissions which have occurred so that the integrated fast flux may be obtained. (AEC)

The effect of cesium carbonate on 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C{sub 61} aggregation in films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindemann, William R.; Wang, Wenjie; Shinar, Joseph

2014-11-10

Surface-pressure versus molecular area isotherms, X-ray reflectivity, and X-ray near-total reflection fluorescence were used to study the properties of 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C{sub 61} (PCBM) that was pre-mixed with cesium carbonate and spread as a film at the air-water interface. The pre-mixed PCBM with cesium carbonate demonstrated a strikingly strong effect on the organization of the film. Whereas films formed from pure PCBM solution were rough due to strong inter-molecular interactions, the films formed from the mixture were much smoother. This indicates that the cesium carbonate moderates the inter-molecular interactions among PCBM molecules, hinting that the cesium diffusion observed in inverted organic photovoltaicmore » structures and the likely ensuing ionic Cs-PCBM interaction decrease aggregation tendency of PCBM. This implies that the use of cesium salts affects the morphology of the organic layer and consequently improves the efficiency of these devices.« less

The effect of cesium carbonate on 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C 61 aggregation in films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindemann, William R.; Wang, Wenjie; Fungura, Fadzai

2014-11-11

Surface-pressure isotherms, X-ray reflectivity, and X-ray near-total reflection fluorescence were used to study the properties of 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C 61 (PCBM) that was pre-mixed with cesium carbonate and spread as a film at the air-water interface. The pre-mixed PCBM with cesium carbonate demonstrated a strikingly strong effect on the organization of the film. Whereas films formed from pure PCBM solution were rough due to strong inter-molecular interactions, the films formed from the mixture were much smoother. This indicates that the cesium carbonate moderates the inter-molecular interactions among PCBM molecules, hinting that the cesium diffusion observed in inverted organic photovoltaics and the likelymore » ensuing ionic Cs-PCBM interaction decrease aggregation tendency of PCBM. As a result, this implies that the use of cesium salts affects the morphology of the organic layer and consequently improves the efficiency of these devices.« less

CESIUM RECOVERY FROM AQUEOUS SOLUTIONS

DOEpatents

Schneider, R.A.

1961-06-20

Cesium may be precipitated from an aqueous solution whose acidity ranges between a pH of 1.5 and a molarity of 5 on cobaltous, zinc, cadmium, nickel, or ferrous cobalticyanide. This precipitation brings about a separation from most fission products. Ruthenium which coprecipitates to a great degree can be removed by dissolving in sulfuric acid and boiling the solution in the presence of periodic acid for volatilization; other coprecipitated fission products can then be precipitated from the sulfuric acid solution with a ferric hydroxide carrier.

Apparatus for generating coherent infrared energy of selected wavelength

DOEpatents

Stevens, C.G.

A tunable source of coherent infrared energy includes a heat pipe having an intermediate region at which cesium is heated to vaporizing temperature and end regions at which the vapor is condensed and returned to the intermediate region for reheating and recirculation. Optical pumping light is directed along the axis of the heat pipe through a first end window to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window. A porous walled tubulation extends along the axis of the heat pipe and defines a region in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light. Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light.

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

PubMed

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

2014-04-15

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 2h. 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 2h). 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. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Fiskum, Sandra K.; Smoot, Margaret R.

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 conductedmore » 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..« less

Efficient non-linear two-photon effects from the Cesium 6D manifold

NASA Astrophysics Data System (ADS)

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.

ETV REPORT: REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING WATER — ECOWATER SYSTEMS, INC. ERO-R450E WATER TREATMENT SYSTEM

EPA Science Inventory

The EcoWater Systems ERO-R450E POU drinking water treatment system was tested for removal of aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury, mevinphos, oxamyl, strontium, and strychnine. The ERO-R450E employs a reverse os...

ETV REPORT: REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING WATER – WATTS PREMIER INC. WP-4V DRINKING WATER TREATMENT SYSTEM

EPA Science Inventory

The Watts Premier WP-4V POU drinking water treatment system was tested for removal of aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury, mevinphos, oxamyl, strontium, and strychnine. The WP-4V employs a reverse osmosis (RO) m...

Adsorption of Radioactive Cesium to Illite-Sericite Mixed Clays

NASA Astrophysics Data System (ADS)

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).

Cesium vapor cycle for an advanced LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

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$sup 0$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 cesiummore » 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. (auth)« less

REMOVAL OF CHEMICAL AND MICROBIAL CONTAMINANTS IN DRINKING WATER - WATTS PREMIER M-2400 POINT-OF-ENTRY REVERSE OSMOSIS DRINKINGWATER TREATMENT SYSTEM

EPA Science Inventory

The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking Water Treatment Systems Laboratory for removal of the viruses fr and MS2, the bacteria Brevundimonas diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chl...

Removal of radioactive and other hazardous material from fluid waste

DOEpatents

Tranter, Troy J [Idaho Falls, ID; Knecht, Dieter A [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Burchfield, Larry A [W. Richland, WA; Anshits, Alexander G [Krasnoyarsk, RU; Vereshchagina, Tatiana [Krasnoyarsk, RU; Tretyakov, Alexander A [Zheleznogorsk, RU; Aloy, Albert S [St. Petersburg, RU; Sapozhnikova, Natalia V [St. Petersburg, RU

2006-10-03

Hollow glass microspheres obtained from fly ash (cenospheres) are impregnated with extractants/ion-exchangers and used to remove hazardous material from fluid waste. In a preferred embodiment the microsphere material is loaded with ammonium molybdophosphonate (AMP) and used to remove radioactive ions, such as cesium-137, from acidic liquid wastes. In another preferred embodiment, the microsphere material is loaded with octyl(phenyl)-N-N-diisobutyl-carbamoylmethylphosphine oxide (CMPO) and used to remove americium and plutonium from acidic liquid wastes.

Biosorption behavior and mechanism of cesium-137 on Rhodosporidium fluviale strain UA2 isolated from cesium solution.

PubMed

Lan, Tu; Feng, Yue; Liao, Jiali; Li, Xiaolong; Ding, Congcong; Zhang, Dong; Yang, Jijun; Zeng, Junhui; Yang, Yuanyou; Tang, Jun; Liu, Ning

2014-08-01

In order to identify a more efficient biosorbent for (137)Cs, we have investigated the biosorption behavior and mechanism of (137)Cs on Rhodosporidium fluviale (R. fluviale) strain UA2, one of the dominant species of a fungal group isolated from a stable cesium solution. We observed that the biosorption of (137)Cs on R. fluviale strain UA2 was a fast and pH-dependent process in the solution composed of R. fluviale strain UA2 (5 g/L) and cesium (1 mg/L). While a Langmuir isotherm equation indicated that the biosorption of (137)Cs was a monolayer adsorption, the biosorption behavior implied that R. fluviale strain UA2 adsorbed cesium ions by electrostatic attraction. The TEM analysis revealed that cesium ions were absorbed into the cytoplasm of R. fluviale strain UA2 across the cell membrane, not merely fixed on the cell surface, which implied that a mechanism of metal uptake contributed largely to the cesium biosorption process. Moreover, PIXE and EPBS analyses showed that ion-exchange was another biosorption mechanism for the cell biosorption of (137)Cs, in which the decreased potassium ions were replaced by cesium ions. All the above results implied that the biosorption of (137)Cs on R. fluviale strain UA2 involved a two-step process. The first step is passive biosorption that cesium ions are adsorbed to cells surface by electrostatic attraction; after that, the second step is active biosorption that cesium ions penetrate the cell membrane and accumulate in the cytoplasm. Copyright © 2014 Elsevier Ltd. All rights reserved.

Apparatus for generating coherent infrared energy of selected wavelength

DOEpatents

Stevens, Charles G.

1985-01-01

A tunable source (11) of coherent infrared energy includes a heat pipe (12) having an intermediate region (24) at which cesium (22) is heated to vaporizing temperature and end regions (27, 28) at which the vapor is condensed and returned to the intermediate region (24) for reheating and recirculation. Optical pumping light (43) is directed along the axis of the heat pipe (12) through a first end window (17) to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window (18). A porous walled tubulation (44) extends along the axis of the heat pipe (12) and defines a region (46) in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light (43). Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light (43).

Sericitization of illite decreases sorption capabilities for cesium

NASA Astrophysics Data System (ADS)

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 (i.e., frayed edge sites).

Development of High Quantum Efficiency UV/Blue Photocathode Epitaxial Semiconductor Heterostructures for Scintillation and Cherenkov Radiation Detection

NASA Technical Reports Server (NTRS)

Leopold, Daniel J.

2002-01-01

The primary goal of this research project was to further extend the use of advanced heteroepitaxial-semiconductor crystal growth techniques such as molecular beam epitaxy (MBE) and to demonstrate significant gains in UV/blue photonic detection by designing and fabricating atomically-tailored heteroepitaxial GaAlN/GaInN photocathode device structures. This NASA Explorer technology research program has focused on the development of photocathodes for Cherenkov and scintillation radiation detection. Support from the program allowed us to enhance our MBE system to include a nitrogen plasma source and a magnetic bearing turbomolecular pump for delivery and removal of high purity atomic nitrogen during GaAlN/GaInN film growth. Under this program we have also designed, built and incorporated a cesium activation stage. In addition, a connected UHV chamber with photocathode transfer/positioner components as well as a hybrid phototube stage was designed and built to make in-situ quantum efficiency measurements without ever having to remove the photocathodes from UHV conditions. Thus we have constructed a system with the capability to couple atomically-tailored MBE-grown photocathode heterostructures with real high gain readout devices for single photon detection evaluation.

Study of radiatively sustained cesium plasmas for solar energy conversion

NASA Technical Reports Server (NTRS)

Palmer, A. J.; Dunning, G. J.

1980-01-01

The results of a study aimed at developing a high temperature solar electric converter are reported. The converter concept is based on the use of an alkali plasma to serve as both an efficient high temperature collector of solar radiation as well as the working fluid for a high temperature working cycle. The working cycle is a simple magnetohydrodynamic (MHD) Rankine cycle employing a solid electrode Faraday MHD channel. Research milestones include the construction of a theoretical model for coupling sunlight in a cesium plasma and the experimental demonstration of cesium plasma heating with a solar simulator in excellent agreement with the theory. Analysis of a solar MHD working cycle in which excimer laser power rather than electric power is extracted is also presented. The analysis predicts a positive gain coefficient on the cesium-xenon excimer laser transition.

Copper Ferrocyanide Functionalized Core-Shell Magnetic Silica Composites for the Selective Removal of Cesium Ions from Radioactive Liquid Waste.

PubMed

Lee, Hyun Kyu; Yang, Da Som; Oh, Wonzin; Choi, Sang-June

2016-06-01

The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.

Low level detection of Cs-135 and Cs-137 in environmental samples by ICP-MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liezers, Martin; Farmer, Orville T.; Thomas, Linda MP

2009-10-01

The measurement of the fission product cesium isotopes 135Cs and 137Cs at low femtogram (fg) 10-15 levels in ground water by Inductively Coupled Plasma-Mass Spectrometry ICP-MS is reported. To eliminate the potential natural barium isobaric interference on the cesium isotopes, in-line chromatographic separation of the cesium from barium was performed followed by high sensitivity ICP-MS analysis. A high efficiency desolvating nebulizer system was employed to maximize ICP-MS sensitivity ~10cps/femtogram. The three sigma detection limit measured for 135Cs was 2fg/ml (0.1uBq/ml) and for 137Cs 0.9fg/ml (0.0027Bq/ml) with analysis time of less than 30 minutes/sample. Cesium detection and 135/137 isotope ratio measurementmore » at very low femtogram levels using this method in a ground water matrix is also demonstrated.« less

SUPPLEMENTAL ANALYSES FOR SOLVENT HOLD TANK SAMPLES MCU-11-314, MCU-11-315, MCU-11-316, MCU-11-317, MCU-11-318 AND MCU-11-319

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T.; Washington, A; . Fondeur, F.

2011-09-29

Savannah River National Laboratory (SRNL) periodically analyses solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-11-314, MCU-11-315, MCU-11-316, MCU-11-317, MCU-11-318 and MCU-11-319 have been previously reported. MCU has experienced a modest decline in cesium removal efficiency while processing the current feed, 'Macrobatch 3'. While the target decontamination factor (DF) is 200, the fiscal year 2011 DF average is 161. The results of the prior solvent analysis report did notmore » identify a specific factor that would correlate with the poor cesium decontamination beyond a low concentration of the suppressor, trioctylamine. New analyses of the quarterly sample are reported in this document, as well as a cross-check of {sup 137}Cs measurements for SRNL and F/H lab. Furthermore, in an attempt to discover the reason for the decline in DF at MCU, SRNL was tasked with analyzing numerous Caustic Wash Tank (CWT) and chemical feed samples.« less

Noble gas, iodine, and cesium transport in a postulated loss of decay heat removal accident at Browns Ferry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wichner, R.P.; Hodge, S.A.; Weber, C.F.

1984-08-01

This report presents an analysis of the movement of noble gas, iodine, and cesium fission products within the Mark-I containment BWR reactor system represented by Browns Ferry Unit 1 during a postulated accident sequence initiated by a loss of decay heat removal capability following a scram. The event analysis showed that this accident could be brought under control by various means, but the sequence with no operator action ultimately leads to containment (drywell) failure followed by loss of water from the reactor vessel, core degradation due to overheating, and reactor vessel failure with attendant movement of core debris onto themore » drywell floor. The analysis of fission product transport presented in this report is based on the no-operator-action sequence and provides an estimate of fission product inventories, as a function of time, within 14 control volumes outside the core, with the atmosphere considered as the final control volume in the transport sequence. As in the case of accident sequences previously studied, we find small barrier for noble gas ejection to air, these gases being effectively purged from the drywell and reactor building by steam and concrete degradation gases. However, significant decay of krypton isotopes occurs during the long delay times involved in this sequence. In contrast, large degrees of holdup for iodine and cesium are projected due to the chemical reactivity of these elements. Only about 2 x 10/sup -4/% of the initial iodine and cesium activity are predicted to be released to the atmosphere. Principal barriers for release are deposition on reactor vessel and containment walls. A significant amount of iodine is captured in the water pool formed in the reactor building basement after actuation of the fire protection system.« less

The Effect of Pressure and Organic Constituents on the Cesium Ion Exchange Performance of IONSIV IE-911

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fondeur, F.F.

2000-07-18

This study examined cesium ({sup 137}Cs) ion exchange of crystalline silicotitanate (CST) in simulated waste solution. In particular, the study focused on the effect of CST pretreatment on the kinetics and extent of cesium adsorption. The test used IONSIV{reg_sign}IE-911 (UOP LLC, Molecular Sieves Division, Des Plaines, IL), the engineered form of CST. Pretreatment steps examined include: soaking CST in 2M NaOH solution for three days, exposing CST to 50% relative humidity for one week, flowing organic-containing (saturated) salt solution through a CST packed bed (at 5 cm/min. superficial velocity), or drying CST in air at 100 C for three days.more » Some tests occurred under 50 and 25 psig of argon. The following conclusions summarize the results. Pretreatment of IE-911 in organic-containing (e.g., tri-n-butyl phosphate, dibutylphosphate, butanol, paraffin and Dow Corning H-10 defoamer) simulated waste or simulated waste yielded a 83% slower rate of cesium adsorption and 56% lower cesium capacity after one week. Pretreatment of IE-911 in 2M caustic solution for 48 hours yielded a slower approach to equilibrium cesium distribution in batch contact tests--7.7 mL/(g*h) during the first 48 hours and 2.4 ml/(g*h) thereafter. Carboxylates and adsorbed carbonates inside the pores likely affect the cesium transport by either increasing the path-length or reducing mass transfer rate. Heating IE-911 as received from the vendor at 100 C for 24 hours significantly degraded its cesium removal performance by a 40.7% reduction in capacity and 43% reduction in sorption rate over one week of testing. Testing determined nearly identical distribution coefficients K{sub d} between lot {number_sign} 9990-9681-0004 and 9990-9881-0005 (i.e., difference of only 5.6%). Tests measuring water insertion rates into IE-911 show that hydration of the IE-911 does not appear to limit the rate of cesium sorption. Increasing the atmospheric pressure from 0 to 50 psig had no effect on cesium sorption. Note that lower apparent capacity or slower cesium sorption rate in these limited-duration batch contact tests as a result of pretreatment do not necessarily imply reduced dynamic performance in a flowing ion-exchange application. The experiments that provided the bases for the currently proposed facility design used caustic-pretreated IE-911. Another report will assess whether the presence of the organic compounds in the waste solution impeded column performance.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 filmsmore » (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)« less

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

PubMed

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.

Tungstate-based glass-ceramics for the immobilization of radio cesium

NASA Astrophysics Data System (ADS)

Drabarek, Elizabeth; McLeod, Terry I.; Hanna, John V.; Griffith, Christopher S.; Luca, Vittorio

2009-02-01

The preparation of tungstate-containing glass-ceramic composites (GCC) for the potential immobilization of radio cesium has been considered. The GCC materials were prepared by blending two oxide precursor compositions in various proportions. These included a preformed Cs-containing hexagonal tungsten bronze (HTB) phase (Cs 0.3Ti 0.2W 0.8O 3, P6 3/ mcm) and a blend of silica and other oxides. The use of the HTB phase was motivated on the assumption that a HTB-based adsorbent could be used to remove cesium directly from aqueous high level liquid waste feeds. In the absence of the HTB, glass-ceramics were relatively easily prepared from the Cs-containing glass-forming oxide blend. On melting the mixture a relative complex GCC phase assemblage formed. The principal components of this phase assemblage were determined using X-ray powder diffraction, 133Cs MAS-NMR, and cross-sectional SEM and included glass, various zeolites, scheelite (CaWO 4) and a range of other oxide phases and Cs-containing aluminosilicate. Importantly, under no circumstance was cesium partitioned into the glass phase irrespective of whether or not the composition included the preformed Cs-containing HTB compound. For compositions containing the HTB, cesium was partitioned into one of four major phases including zeolite; Cs-silica-tungstate bronze, pollucite (CsAlSi 2O 6), and an aluminosilicate with an Al/Si ratio close to one. The leach resistance of all materials was evaluated and related to the cesium distribution within the GCC phase assemblages. In general, the GCCs prepared from the HTB had superior durability compared with materials not containing tungsten. Indeed the compositions in many cases had leach resistances comparable to the best ceramics or glass materials.

Accumulation of Radioactive Cesium Released from Fukushima Daiichi Nuclear Power Plant in Terrestrial Cyanobacteria Nostoc commune

PubMed Central

Sasaki, Hideaki; Shirato, Susumu; Tahara, Tomoya; Sato, Kenji; Takenaka, Hiroyuki

2013-01-01

The Fukushima Daiichi Nuclear Power Plant accident released large amounts of radioactive substances into the environment and contaminated the soil of Tohoku and Kanto districts in Japan. Removal of radioactive material from the environment is an urgent problem, and soil purification using plants is being considered. In this study, we investigated the ability of 12 seed plant species and a cyanobacterium to accumulate radioactive material. The plants did not accumulate radioactive material at high levels, but high accumulation was observed in the terrestrial cyanobacterium Nostoc commune. In Nihonmatsu City, Fukushima Prefecture, N. commune accumulated 415,000 Bq/kg dry weight 134Cs and 607,000 Bq kg−1 dry weight 137Cs. The concentration of cesium in N. commune tended to be high in areas where soil radioactivity was high. A cultivation experiment confirmed that N. commune absorbed radioactive cesium from polluted soil. These data demonstrated that radiological absorption using N. commune might be suitable for decontaminating polluted soil. PMID:24256969

Selective Capture of Cesium and Thallium from Natural Waters and Simulated Wastes with Copper Ferrocyanide Functionalized Mesoporous Silica

PubMed Central

Sangvanich, Thanapon; Sukwarotwat, Vichaya; Wiacek, Robert J.; Grudzien, Rafal M.; Fryxell, Glen E.; Addleman, R. Shane; Timchalk, Charles; Yantasee, Wassana

2010-01-01

Copper(II) ferrocyanide on mesoporous silica (FC-Cu-EDA-SAMMS™) has been evaluated against iron(III) hexacyanoferrate(II) (insoluble Prussian Blue) for removing cesium (Cs+) and thallium (Tl+) from natural waters and simulated acidic and alkaline wastes. From pH 0.1 – 7.3, FC-Cu-EDA-SAMMS had greater affinities for Cs and Tl and was less affected by the solution pH, competing cations, and matrices. SAMMS also outperformed Prussian Blue in terms of adsorption capacities (e.g., 21.7 versus 2.6 mg Cs/g in acidic waste stimulant (pH 1.1), 28.3 versus 5.8 mg Tl/g in seawater), and rate (e.g., over 95 wt% of Cs was removed from seawater after 2 min with SAMMS, while only 75 wt% was removed with Prussian Blue). SAMMS also had higher stability (e.g., 2.5 to 13-fold less Fe dissolved from 2 to 24 hr of contact time). In addition to environmental applications, SAMMS has great potential to be used as orally administered drug for limiting the absorption of radioactive Cs and toxic Tl in gastrointestinal tract. PMID:20594644

CsIX/TRU Grout Feasibility Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. J. Losinski; C. M. Barnes; B. K. Grover

A settlement agreement between the Department of Energy (DOE) and the State of Idaho mandates that liquid waste now stored at the Idaho Nuclear Technology Engineering Center (INTEC - formerly the Idaho Chemical Processing Plant, ICPP) will be calcined by the end of year 2012. This study investigates an alternative treatment of the liquid waste that removes undissolved solids (UDS) by filtration and removes cesium by ion exchange followed by cement-based grouting of the remaining liquid into 55-gal drums. Operations are assumed to be from January 2008 through December 2012. The grouted waste will be contact-handled and will be shippedmore » to the Waste Isolation Pilot Plant (WIPP) in New Mexico for disposal. The small volume of secondary wastes such as the filtered solids and cesium sorbent (resin) would remain in storage at the Idaho National Engineering and Environmental Laboratory for treatment and disposal under another project, with an option to dispose of the filtered solids as a r emote-handled waste at WIPP.« less

Decontamination of radiological agents from drinking water infrastructure: a literature review and summary.

PubMed

Szabo, Jeff; Minamyer, Scott

2014-11-01

This report summarizes the current state of knowledge on the persistence of radiological agents on drinking water infrastructure (such as pipes) along with information on decontamination should persistence occur. Decontamination options for drinking water infrastructure have been explored for some important radiological agents (cesium, strontium and cobalt), but important data gaps remain. Although some targeted experiments have been published on cesium, strontium and cobalt persistence on drinking water infrastructure, most of the data comes from nuclear clean-up sites. Furthermore, the studies focused on drinking water systems use non-radioactive surrogates. Non-radioactive cobalt was shown to be persistent on iron due to oxidation with free chlorine in drinking water and precipitation on the iron surface. Decontamination with acidification was an effective removal method. Strontium persistence on iron was transient in tap water, but adherence to cement-mortar has been demonstrated and should be further explored. Cesium persistence on iron water infrastructure was observed when flow was stagnant, but not with water flow present. Future research suggestions focus on expanding the available cesium, strontium and cobalt persistence data to other common infrastructure materials, specifically cement-mortar. Further exploration chelating agents and low pH treatment is recommended for future decontamination studies. Published by Elsevier Ltd.

Removal of Radionuclides from Waste Water at Fukushima Daiichi Nuclear Power Plant: Desalination and Adsorption Methods - 13126

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kani, Yuko; Kamosida, Mamoru; Watanabe, Daisuke

Waste water containing high levels of radionuclides due to the Fukushima Daiichi Nuclear Power Plant accident, has been treated by the adsorption removal and reverse-osmosis (RO) desalination to allow water re-use for cooling the reactors. Radionuclides in the waste water are collected in the adsorbent medium and the RO concentrate (RO brine) in the water treatment system currently operated at the Fukushima Daiichi site. In this paper, we have studied the behavior of radionuclides in the presently applied RO desalination system and the removal of radionuclides in possible additional adsorption systems for the Fukushima Daiichi waste water treatment. Regarding themore » RO desalination system, decontamination factors (DFs) of the elements present in the waste water were obtained by lab-scale testing using an RO unit and simulated waste water with non-radioactive elements. The results of the lab-scale testing using representative elements showed that the DF for each element depended on its hydrated ionic radius: the larger the hydrated ionic radius of the element, the higher its DF is. Thus, the DF of each element in the waste water could be estimated based on its hydrated ionic radius. For the adsorption system to remove radionuclides more effectively, we studied adsorption behavior of typical elements, such as radioactive cesium and strontium, by various kinds of adsorbents using batch and column testing. We used batch testing to measure distribution coefficients (K{sub d}s) for cesium and strontium onto adsorbents under different brine concentrations that simulated waste water conditions at the Fukushima Daiichi site. For cesium adsorbents, K{sub d}s with different dependency on the brine concentration were observed based on the mechanism of cesium adsorption. As for strontium, K{sub d}s decreased as the brine concentration increased for any adsorbents which adsorbed strontium by intercalation and by ion exchange. The adsorbent titanium oxide had higher K{sub d}s and it was used for the column testing to obtain breakthrough curves under various conditions of pH and brine concentration. The breakthrough point had a dependency on pH and the brine concentration. We found that when the pH was higher or the brine concentration was lower, the longer it took to reach the breakthrough point. The inhibition of strontium adsorption by alkali earth metals would be diminished for conditions of higher pH and lower brine concentration. (authors)« less

Enhanced desorption of cesium from collapsed interlayer regions in vermiculite by hydrothermal treatment with divalent cations.

PubMed

Yin, Xiangbiao; Wang, Xinpeng; Wu, Hao; Ohnuki, Toshihiko; Takeshita, Kenji

2017-03-15

Adsorption of cesium (Cs) on phyllosilicates has been intensively investigated because natural soils have strong ability of immobilizing Cs within clay minerals resulting in difficulty of decontamination. The objectives of present study are to clarify how Cs fixation on vermiculite is influenced by structure change caused by Cs sorption at different loading levels and how Cs desorption is affected by various replacing cations induced at different treating temperature. As a result, more than 80% of Cs was readily desorbed from vermiculite with loading amount of 2% saturated Cs (5.49×10 -3 mmolg -1 ) after four cycles of treatment of 0.01M Mg 2+ /Ca 2+ at room temperature, but less than 20% of Cs was desorbed from saturated vermiculite. These distinct desorption patterns were attributed to inhibition of Cs desorption by interlayer collapse of vermiculite, especially at high Cs loadings. In contrast, elevated temperature significantly facilitated divalent cations to efficiently desorb Cs from collapsed regions. After five cycles of treatment at 250°C with 0.01M Mg 2+ , ∼100% removal of saturated Cs was achieved. X-ray diffraction analysis results suggested that Cs desorption was completed through enhanced diffusion of Mg 2+ cations into collapsed interlayer space under hydrothermal condition resulting in subsequent interlayer decollapse and readily release of Cs + . Copyright © 2016 Elsevier B.V. All rights reserved.

Immobilized nickel hexacyanoferrate on activated carbons for efficient attenuation of radio toxic Cs(I) from aqueous solutions

NASA Astrophysics Data System (ADS)

Lalhmunsiama; Lalhriatpuia, C.; Tiwari, Diwakar; Lee, Seung-Mok

2014-12-01

The aim of this study is to immobilize nickel hexacyanoferrate onto the large surface of activated carbons (ACs) precursor to rice hulls and areca nut waste materials. These nickel hexacyanoferrate immobilized materials are then assessed in the effective attenuation of radio logically important cesium ions from aqueous solutions. The solid samples are characterized by the XRD analytical method and surface morphology is obtained from the SEM images. The batch reactor experiments show that an increase in sorptive pH (2.0-10.0) apparently not affecting the high percent uptake of Cs(I). Equilibrium modeling studies suggest that the data are reasonably and relatively fitted well to the Langmuir adsorption isotherm. Kinetic studies show that sorption process is fairly rapid and the kinetic data are fitted well to the pseudo-second order rate model. Increasing the background electrolyte concentration from 0.001 to 0.1 mol/L NaCl causes insignificant decrease in Cs(I) removal which infers the higher selectivity of these materials for Cs(I) from aqueous solutions. Further, the column reactor operations enable to obtain the breakthrough data which are then fitted to the Thomas non-linear equation as to obtain the loading capacity of column for Cs(I). The results show that the modified materials show potential applicability in the attenuation of radio toxic cesium from aqueous solution.

Measurements of cesium in Arctic beluga and caribou before and after the Fukushima accident of 2011.

PubMed

Stocki, T J; Gamberg, M; Loseto, L; Pellerin, E; Bergman, L; Mercier, J-F; Genovesi, L; Cooke, M; Todd, B; Sandles, D; Whyte, J; Wang, X

2016-10-01

Concern from northern communities following the Fukushima Daiichi nuclear accident of March 2011 has prompted a reassessment of the safety of their traditional foods with respect to radioactivity levels. To this end, a study was conducted to measure the levels of radionuclides in Arctic caribou (Rangifer tarandus) and beluga (Delphinapterus leucas). The main radionuclide of concern is cesium-137, which is easily transferred through the lichen-caribou food chain. Previous studies have been conducted on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl nuclear accident in 1986. In this study, samples of lichens, mushrooms, caribou, beluga and beluga prey collected before and after the Fukushima accident were analyzed for radioactivity levels. Samples were processed and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration. Both calibration standards and Monte Carlo simulations were used to determine the efficiency of the detectors for the samples, taking into account differences in individual sample sizes as well as matrices. In particular, a careful analysis of the atomic composition of lichens and mushrooms was performed to ensure the efficiencies for these sample types were correct. A comparison of the concentrations from before and after the accident indicated that there was no increase in radioactivity as a result of the atmospheric plume from the Fukushima accident. Some cesium-137, likely attributable to fallout from atmospheric weapons testing of the 1950s and 1960s (since there was no cesium-134 measured in the samples), was measured in the post Fukushima caribou and beluga whale samples; however, this amount was determined to be insignificant for any radiological concern (9.1 ± 1.8 and 0.63 ± 0.23 Bq kg -1  ww respectively). The activity concentrations of cesium-137 was about 200 times smaller than that of natural radioactive potassium in the beluga samples. Both the caribou and beluga results showed that these foods continue to be a healthy food choice for northern Canadians with respect to radioactivity, and this result has been communicated to the nearby northern communities and stakeholders. Copyright © 2016. Published by Elsevier Ltd.

Optical and structural properties of CsI thin film photocathode

NASA Astrophysics Data System (ADS)

Triloki; Rai, R.; Singh, B. K.

2015-06-01

In the present work, the performance of a cesium iodide thin film photocathode is studied in detail. The optical absorbance of cesium iodide films has been analyzed in the spectral range from 190 nm to 900 nm. The optical band gap energy of 500 nm thick cesium iodide film is calculated from the absorbance data using a Tauc plot. The refractive index is estimated from the envelope plot of transmittance data using Swanepoel's method. The absolute quantum efficiency measurement has been carried out in the wavelength range from 150 nm to 200 nm. The crystallographic nature and surface morphology are investigated by X-ray diffraction and transmission electron microscopy techniques. In addition, the elemental composition result obtained by energy dispersive X-ray analysis is also reported in the present work.

Purification of Bacteriophages Using Anion-Exchange Chromatography.

PubMed

Vandenheuvel, Dieter; Rombouts, Sofie; Adriaenssens, Evelien M

2018-01-01

In bacteriophage research and therapy, most applications ask for highly purified phage suspensions. The standard technique for this is ultracentrifugation using cesium chloride gradients. This technique is cumbersome, elaborate and expensive. Moreover, it is unsuitable for the purification of large quantities of phage suspensions.The protocol described here, uses anion-exchange chromatography to bind phages to a stationary phase. This is done using an FLPC system, combined with Convective Interaction Media (CIM ® ) monoliths. Afterward, the column is washed to remove impurities from the CIM ® disk. By using a buffer solution with a high ionic strength, the phages are subsequently eluted from the column and collected. In this way phages can be efficiently purified and concentrated.This protocol can be used to determine the optimal buffers, stationary phase chemistry and elution conditions, as well as the maximal capacity and recovery of the columns.

Polymer-Passivated Inorganic Cesium Lead Mixed-Halide Perovskites for Stable and Efficient Solar Cells with High Open-Circuit Voltage over 1.3 V.

PubMed

Zeng, Qingsen; Zhang, Xiaoyu; Feng, Xiaolei; Lu, Siyu; Chen, Zhaolai; Yong, Xue; Redfern, Simon A T; Wei, Haotong; Wang, Haiyu; Shen, Huaizhong; Zhang, Wei; Zheng, Weitao; Zhang, Hao; Tse, John S; Yang, Bai

2018-03-01

Cesium-based trihalide perovskites have been demonstrated as promising light absorbers for photovoltaic applications due to their superb composition stability. However, the large energy losses (E loss ) observed in inorganic perovskite solar cells has become a major hindrance impairing the ultimate efficiency. Here, an effective and reproducible method of modifying the interface between a CsPbI 2 Br absorber and polythiophene hole-acceptor to minimize the E loss is reported. It is demonstrated that polythiophene, deposited on the top of CsPbI 2 Br, can significantly reduce electron-hole recombination within the perovskite, which is due to the electronic passivation of surface defect states. In addition, the interfacial properties are improved by a simple annealing process, leading to significantly reduced energy disorder in polythiophene and enhanced hole-injection into the hole-acceptor. Consequently, one of the highest power conversion efficiency (PCE) of 12.02% from a reverse scan in inorganic mixed-halide perovskite solar cells is obtained. Modifying the perovskite films with annealing polythiophene enables an open-circuit voltage (V OC ) of up to 1.32 V and E loss of down to 0.5 eV, which both are the optimal values reported among cesium-lead mixed-halide perovskite solar cells to date. This method provides a new route to further improve the efficiency of perovskite solar cells by minimizing the E loss . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaoying; Liu, Bingwen; Zhao, Evan

For the first time, the use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass, SON68, and layered hole-perovskite oxide thin films were selected as model systems due to their fundamental and practical significance. Our study shows that if the size of analysis areas is same, the highest sputter rate of argon cluster sputtering can be 2-3 times faster than the highest sputtermore » rates of oxygen or cesium sputtering. More importantly, high quality data and high sputter rates can be achieved simultaneously for argon cluster sputtering while this is not the case for cesium and oxygen sputtering. Therefore, for deep depth profiling of insulating samples, the measurement efficiency of argon cluster sputtering can be about 6-15 times better than traditional cesium and oxygen sputtering. Moreover, for a SrTiO3/SrCrO3 bi-layer thin film on a SrTiO3 substrate, the true 18O/16O isotopic distribution at the interface is better revealed when using the argon cluster sputtering source. Therefore, the implementation of an argon cluster sputtering source can significantly improve the measurement efficiency of insulating materials, and thus can expand the application of ToF-SIMS to the study of glass corrosion, perovskite oxide thin films, and many other potential systems.« less

Effective removal of cesium from wastewater solutions using an innovative low-cost adsorbent developed from sewage sludge molten slag.

PubMed

Khandaker, Shahjalal; Toyohara, Yusaku; Kamida, Seiya; Kuba, Takahiro

2018-06-01

This study investigates the effective removal of cesium (Cs) from aqueous solution using sewage sludge molten (SSM) slag that has undergone the surface modification with alkali (NaOH) hydrothermal treatment. The raw and modified slags were characterised systematically using the BET method, the FESEM, the XRF, the XRD spectroscopy and the CEC analysis to understand the physicochemical changes of the materials, and its sensitivity to Cs ions adsorption. Batch adsorption experiments were carried out to investigate the effects of adsorbent dose, contact time, solution pH, different initial Cs concentrations, temperature and the effect of competitive ions on Cs adsorption. The adsorption isotherm, kinetic and thermodynamic studies were also evaluated based on the experimental results. A higher Cs removal efficiency of almost 100% (for 20-100 mg/L of initial concentration) was achieved by the modified SSM slag, and the maximum adsorption capacity was found to be 52.36 mg/g. Several types of synthetic zeolites such as zeolite X, zeolite Y, zeolite A, and sodalite were formed on surface of the modified slag through the modification process which might be enhanced the Cs adsorption capacity. Kinetic parameters were fitted by the pseudo-second order model. The adsorption isotherms data of modified slag were well-fitted to the Langmuir (R 2  = 0.989) and Freundlich isotherms (R 2  = 0.988). The thermodynamic studies indicated that the adsorption process by the modified slag was spontaneous and exothermic. In the competitive ions effect, the modified slag effectively captured the Cs ion in the presence of Na + and K + , especially at their lower concentrations. Moreover, the modified slag was reused for several cycles after the successful elution process with an appropriate eluting agent (0.5 M H 2 SO 4 ), without deterioration of its original performance. Therefore, the SSM modified slag could be effectively used as a low-cost potential adsorbent for high Cs adsorption from wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Engineering a lignocellulosic biosorbent--coir pith for removal of cesium from aqueous solutions: equilibrium and kinetic studies.

PubMed

Parab, Harshala; Sudersanan, M

2010-02-01

A novel method of engineering lignocellulosic biosorbent- coir pith (CP) by incorporation of nickel hexacyanoferrate (NiHCF), also referred to as Prussian blue analogue (PBA) inside its porous matrix is reported. Structural characterization confirmed the successful synthesis of NiHCF in the coir pith matrix. Sorption capacity of coir pith (CP) before and after loading of NiHCF was investigated for cesium (Cs) in batch equilibrium studies. Kinetic studies showed that the sorption process was rapid and saturation was attained within 30 min. The applicability of non linear Langmuir, Freundlich and Redlich Peterson isotherms was examined for the experimental data. The present studies revealed that there was nearly 100% increase in the sorption capacity of CP after its surface modification with NiHCF. Owing to its low cost, fast sorption kinetics and high uptake capacity, coir pith loaded with NiHCF (CP-NiHCF) seems to be one of the most promising biosorbents for recovery of cesium from liquid nuclear wastes. (c) 2009 Elsevier Ltd. All rights reserved.

Spin-injection optical pumping of molten cesium salt and its NMR diagnosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishikawa, Kiyoshi

2015-07-15

Nuclear spin polarization of cesium ions in the salt was enhanced during optical pumping of cesium vapor at high magnetic field. Significant motional narrowing and frequency shift of NMR signals were observed by intense laser heating of the salt. When the hyperpolarized salt was cooled by blocking the heating laser, the signal width and frequency changed during cooling and presented the phase transition from liquid to solid. Hence, we find that the signal enhancement is mostly due to the molten salt and nuclear spin polarization is injected into the salt efficiently in the liquid phase. We also show that opticalmore » pumping similarly induces line narrowing in the solid phase. The use of powdered salt provided an increase in effective surface area and signal amplitude without glass wool in the glass cells.« less

PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

DOEpatents

Spedding, F.H.; Butler, T.A.; Johns, I.B.

1959-03-10

The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

First charge breeding results at CARIBU EBIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondrashev, S., E-mail: kondrashev@anl.gov; Barcikowski, A., E-mail: kondrashev@anl.gov; Dickerson, C., E-mail: kondrashev@anl.gov

The Electron Beam Ion Source (EBIS) developed to breed CARIBU radioactive beams at ATLAS is currently in the off-line commissioning stage. The beam commissioning is being performed using a low emittance surface ionization source producing singly-charged cesium ions. The primary goal of the off-line commissioning is the demonstration of high-efficiency charge breeding in the pulsed injection mode. An overview of the final design of the CARIBU EBIS charge breeder, the off-line commissioning installation and the first results on charge breeding of stable cesium ions are presented and discussed.

Adsorption and Desorption of Cesium in Clay Minerals: Effects of Natural Organic Matter and pH

NASA Astrophysics Data System (ADS)

Yoon, Hongkyu; Ilgen, Anastasia; Mills, Melissa; Lee, Moo; Seol, Jeung Gun; Cho, Nam Chan; Kang, Hyungyu

2017-04-01

Cesium (Cs) released into the environment (e.g., Fukushima accident) poses significant environmental concerns and remediation challenges. A majority of Cs in the environment have remained within the surface soils due to the strong adsorption affinity of Cs towards clay minerals. Different clay minerals have different bonding sites, resulting in various adsorption mechanisms at nanometer scale. For example, the illite commonly has a basal spacing of 1.0 nm, but becomes wider to 1.4 nm once other cations exchange with K in the interlayer site. Cs adsorbs into these expanded wedged zone strongly, which can control its mobility in the environment. In addition, natural organic matter (NOM) in the surface soils can interact with clay minerals, which can modify the mechanisms of Cs adsorption on the clay minerals by blocking specific adsorption sites and/or providing Cs adsorption sites on NOM surface. In this work, three representative clay minerals (illite, vermiculite, montmorillonite) and humic acid (HA) are used to systematically investigate the adsorption and desorption behavior of Cs. We performed batch adsorption experiments over a range of Cs concentrations on three clay minerals with and without HA, followed by sequential desorption batch testing. We tested desorption efficiency as a function of initial adsorbed Cs concentration, HA content, sodium concentration, and pH. The sequential extraction results are compared to the structural changes in clay minerals, measured using extended X-ray absorption fine structure spectroscopy (EXAFS) and aberration-corrected (scanning) transmission electron microscopy (TEM) - energy dispersive X-ray spectroscopy (EDX). Hence, this work aims to identify the mechanisms of Cs fixation at the nanometer (or atomic-) scale as a function of the clay mineral properties (e.g. expandability, permanent surface charge) and varying organic matter content at different pH values and to enhance our atomic-scale mechanistic understanding of the clay mineral interactions with cesium in the presence of NOM. The expandability of clay minerals and effect of HA addition on Cs adsorption and desorption are highlighted to address the efficiency of Cs removal schemes from contaminated soils. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

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

NASA Astrophysics Data System (ADS)

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 were also tested. The final solid product was a hard dense ceramic with a density that varied from 2.12 g/cm3 for a 19% waste loading with a 1200°C sintering temperature to 3.03 g/cm 3 with a 29% waste loading and sintered at 1100°C. Differential Scanning Calorimetry and Thermal Gravimetric Analysis (DSC-TGA) of the loaded bentonite displayed mass loss steps which were consistent with water losses in pure bentonite. Water losses were complete after dehydroxylation at ˜650°C. No mass losses were evident beyond the dehydroxylation. The ceramic melts at temperatures greater than 1300°C. Light flash analysis found heat capacities of the ceramic to be comparable to those of strontium and barium feldspars as well as pollucite. Thermal conductivity improved with higher sintering temperatures, attributed to lower porosity. Porosity was minimized in 1200°C sinterings. Ceramics with waste loadings less than 25 wt% displayed slump, the lowest waste loading, 15 wt% bloated at a 1200°C sintering. Waste loading above 25 wt% produced smooth uniform ceramics when sintered >1100°C. Sintered bentonite may provide a simple alternative to vitrification and other engineered radioactive waste-forms.

Cesium and strontium ion exchange on the framework titanium silicate M2Ti2O3SiO4.nH2O (M = H, Na).

PubMed

Solbrå, S; Allison, N; Waite, S; Mikhalovsky, S V; Bortun, A I; Bortun, L N; Clearfield, A

2001-02-01

The ion exchange properties of the titanium silicate, M2Ti2O3SiO4.nH2O (M = H, Na), toward stable and radioactive 137Cs+ and 89Sr2+, have been examined. By studying the cesium and strontium uptake in the presence of NaNO3, CaCl2, NaOH, and HNO3 (in the range of 0.01-6 M) the sodium titanium silicate was found to be an efficient Cs+ ion exchanger in acid, neutral, and alkaline media and an efficient Sr2+ ion exchanger in neutral and alkaline media, which makes it promising for treatment of contaminated environmental media and biological systems.

Dealing with the aftermath of Fukushima Daiichi nuclear accident: decontamination of radioactive cesium enriched ash.

PubMed

Parajuli, Durga; Tanaka, Hisashi; Hakuta, Yukiya; Minami, Kimitaka; Fukuda, Shigeharu; Umeoka, Kuniyoshi; Kamimura, Ryuichi; Hayashi, Yukie; Ouchi, Masatoshi; Kawamoto, Tohru

2013-04-16

Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to the long living radioisotopes of cesium is an obstacle to speedy recovery from the impacts of the Fukushima Daiichi Nuclear Power Plant accident. Although incineration of the contaminated wastes is encouraged, safe disposal of the Cs enriched ash is the big challenge. To address this issue, safe incineration of contaminated wastes while restricting the release of volatile Cs to the atmosphere was studied. Detailed study on effective removal of Cs from ash samples generated from wood bark, household garbage, and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to (134)Cs and (137)Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cs from sludge ash needed acid treatment at high temperature. This difference in Cs solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense. In addition, need for a long-term leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cs in solids is extracted to the solution, it can be loaded to Cs selective adsorbents such as Prussian blue and safely stored in a small volume.

A review of the Thermoelectronic Laser Energy Converter /TELEC/ Program at Lewis Research Center

NASA Technical Reports Server (NTRS)

Alger, D. L.; Manista, E. J.; Thompson, R. W.

1978-01-01

The investigation of the Thermoelectronic Laser Energy Converter (TELEC) concept at the Lewis Research Center (LeRC) began with a feasibility study of a 1 megawatt sized TELEC system. The TELEC was to use either cesium vapor or hydrogen as the plasma medium. The cesium vapor TELEC appears to be the more practical device studied with an overall calculated conversion efficiency of greater than 48%. Following this study, a small TELEC cell was fabricated which demonstrated the conversion of a small amount of laser power to electrical power. The cell developed a short circuit current of 0.7 amperes and an open circuit voltage, as extrapolated from volt-ampere curves, of about 1.5 volts. Work is now in progress to construct and test a cesium vapor TELEC capable of absorbing 20% of an incident 10 kW, 10.6 micrometer beam, and converting 35% of this power to electrical power.

Electron-transporting layer doped with cesium azide for high-performance phosphorescent and tandem white organic light-emitting devices

NASA Astrophysics Data System (ADS)

Yu, Yaoyao; Chen, Xingming; Jin, Yu; Wu, Zhijun; Yu, Ye; Lin, Wenyan; Yang, Huishan

2017-07-01

Cesium azide was employed as an effective n-dopant in the electron-transporting layer (ETL) of organic light-emitting devices (OLEDs) owing to its low deposition temperature and high ambient stability. By doping cesium azide onto 4,7-diphenyl-1,10-phenanthroline, a green phosphorescent OLED having best efficiencies of 66.25 cd A-1, 81.22 lm W-1 and 18.82% was realized. Moreover, the efficiency roll-off from 1000 cd m-2 to 10 000 cd m-2 is only 12.9%, which is comparable with or even lower than that of devices utilizing the co-host system. Physical mechanisms for the improvement of device performance were studied in depth by analyzing the current density-voltage (J-V) characteristics of the electron-only devices. In particular, by comparing the J-V characteristics of the electron-only devices instead of applying the complicated ultraviolet photoelectron spectrometer measurements, we deduced the decrease in barrier height for electron injection at the ETL/cathode contact. Finally, an efficient tandem white OLED utilizing the n-doped layer in the charge generation unit (CGU) was constructed. As far as we know, this is the first report on the application of this CGU for fabricating tandem white OLEDs. The emissions of the tandem device are all in the warm white region from 1213 cd m-2 to 10870 cd m-2, as is beneficial to the lighting application.

Cesium and strontium extraction using a mixed extractant solvent including crown ether and calixarene extractants

DOEpatents

Meikrantz, David H.; Todd, Terry A.; Riddle, Catherine L.; Law, Jack D.; Peterman, Dean R.; Mincher, Bruce J.; McGrath, Christopher A.; Baker, John D.

2007-11-06

A mixed extractant solvent including calix[4]arene-bis-(tert-octylbenzo)-crown-6 ("BOBCalixC6"), 4',4',(5')-di-(t-butyldicyclo-hexano)-18-crown-6 ("DtBu18C6"), and at least one modifier dissolved in a diluent. The mixed extractant solvent may be used to remove cesium and strontium from an acidic solution. The DtBu18C6 may be present from approximately 0.01 M to approximately 0.4M, such as from approximately 0.086 M to approximately 0.108 M. The modifier may be 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol ("Cs-7SB") and may be present from approximately 0.01M to approximately 0.8M. In one embodiment, the mixed extractant solvent includes approximately 0.15M DtBu18C6, approximately 0.007M BOBCalixC6, and approximately 0.75M Cs-7SB modifier dissolved in an isoparaffinic hydrocarbon diluent. The mixed extractant solvent may form an organic phase in an extraction system that also includes an aqueous phase. Methods of extracting cesium and strontium as well as strontium alone are also disclosed.

Novel Fission-Product Separation based on Room-Temperature Ionic Liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Robin D.

2004-12-31

U.S. DOE's underground storage tanks at Hanford, SRS, and INEEL contain liquid wastes with high concentrations of radioactive cesium-137 and strontium-90. Because the primary chemical components of alkaline supernatants are sodium nitrate and sodium hydroxide, the majority of this could be disposed of as low level waste if radioactive cesium-137 and strontium- 90 could be selectively removed. The underlying goal of this project was to investigate the application of ionic liquids as novel solvents for new solvent extraction processes for separation of cesium-137 and strontium-90 from tank wastes. Ionic liquids are a distinct sub-set of liquids, comprising only of cationsmore » and anions they are proving to be increasingly interesting fluids for application in systems from electrochemistry to energetic materials, and are also rapidly establishing their promise as viable media for synthesis and separations operations. Properties including low melting points, electrochemical conductivity, wide liquid ranges, lack of vapor-pressure, and chemical tunability have encouraged researchers to explore the uses of ILs in place of volatile organic solvents. The most promising current developments arise from control of the unique combinations of chemical and physical properties characteristic of ionic liquids.« less

Cesium-137 deposition and contamination of Japanese soils due to the Fukushima nuclear accident.

PubMed

Yasunari, Teppei J; Stohl, Andreas; Hayano, Ryugo S; Burkhart, John F; Eckhardt, Sabine; Yasunari, Tetsuzo

2011-12-06

The largest concern on the cesium-137 ((137)Cs) deposition and its soil contamination due to the emission from the Fukushima Daiichi Nuclear Power Plant (NPP) showed up after a massive quake on March 11, 2011. Cesium-137 ((137)Cs) with a half-life of 30.1 y causes the largest concerns because of its deleterious effect on agriculture and stock farming, and, thus, human life for decades. Removal of (137)Cs contaminated soils or land use limitations in areas where removal is not possible is, therefore, an urgent issue. A challenge lies in the fact that estimates of (137)Cs emissions from the Fukushima NPP are extremely uncertain, therefore, the distribution of (137)Cs in the environment is poorly constrained. Here, we estimate total (137)Cs deposition by integrating daily observations of (137)Cs deposition in each prefecture in Japan with relative deposition distribution patterns from a Lagrangian particle dispersion model, FLEXPART. We show that (137)Cs strongly contaminated the soils in large areas of eastern and northeastern Japan, whereas western Japan was sheltered by mountain ranges. The soils around Fukushima NPP and neighboring prefectures have been extensively contaminated with depositions of more than 100,000 and 10,000 MBq km(-2), respectively. Total (137)Cs depositions over two domains: (i) the Japan Islands and the surrounding ocean (130-150 °E and 30-46 °N) and, (ii) the Japan Islands, were estimated to be approximately 6.7 and 1.3 PBq, [corrected] respectively.We hope our (137)Cs deposition maps will help to coordinate decontamination efforts and plan regulatory measures in Japan.

Development of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) Process for Cesium Removal from High-Level Tank Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moyer, Bruce A; Bonnesen, Peter V; Delmau, Laetitia Helene

2011-01-01

This paper describes the chemical performance of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) process in its current state of development for removal of cesium from the alkaline high-level tank wastes at the Savannah River Site (SRS) in the US Department of Energy (USDOE) complex. Overall, motivation for seeking a major enhancement in performance for the currently deployed CSSX process stems from needs for accelerating the cleanup schedule and reducing the cost of salt-waste disposition. The primary target of the NG-CSSX development campaign in the past year has been to formulate a solvent system and to design a corresponding flowsheet thatmore » boosts the performance of the SRS Modular CSSX Unit (MCU) from a current minimum decontamination factor of 12 to 40,000. The chemical approach entails use of a more soluble calixarene-crown ether, called MaxCalix, allowing the attainment of much higher cesium distribution ratios (DCs) on extraction. Concurrently decreasing the Cs-7SB modifier concentration is anticipated to promote better hydraulics. A new stripping chemistry has been devised using a vitrification-friendly aqueous boric acid strip solution and a guanidine suppressor in the solvent, resulting in sharply decreased DCs on stripping. Results are reported herein on solvent phase behavior and batch Cs distribution for waste simulants and real waste together with a preliminary flowsheet applicable for implementation in the MCU. The new solvent will enable MCU to process a much wider range of salt feeds and thereby extend its service lifetime beyond its design life of three years. Other potential benefits of NG-CSSX include increased throughput of the SRS Salt Waste Processing Facility (SWPF), currently under construction, and an alternative modular near-tank application at Hanford.« less

Cesium-137 deposition and contamination of Japanese soils due to the Fukushima nuclear accident

PubMed Central

Yasunari, Teppei J.; Stohl, Andreas; Hayano, Ryugo S.; Burkhart, John F.; Eckhardt, Sabine; Yasunari, Tetsuzo

2011-01-01

The largest concern on the cesium-137 (137Cs) deposition and its soil contamination due to the emission from the Fukushima Daiichi Nuclear Power Plant (NPP) showed up after a massive quake on March 11, 2011. Cesium-137 (137Cs) with a half-life of 30.1 y causes the largest concerns because of its deleterious effect on agriculture and stock farming, and, thus, human life for decades. Removal of 137Cs contaminated soils or land use limitations in areas where removal is not possible is, therefore, an urgent issue. A challenge lies in the fact that estimates of 137Cs emissions from the Fukushima NPP are extremely uncertain, therefore, the distribution of 137Cs in the environment is poorly constrained. Here, we estimate total 137Cs deposition by integrating daily observations of 137Cs deposition in each prefecture in Japan with relative deposition distribution patterns from a Lagrangian particle dispersion model, FLEXPART. We show that 137Cs strongly contaminated the soils in large areas of eastern and northeastern Japan, whereas western Japan was sheltered by mountain ranges. The soils around Fukushima NPP and neighboring prefectures have been extensively contaminated with depositions of more than 100,000 and 10,000 MBq km-2, respectively. Total 137Cs depositions over two domains: (i) the Japan Islands and the surrounding ocean (130–150 °E and 30–46 °N) and, (ii) the Japan Islands, were estimated to be more than 5.6 and 1.0 PBq, respectively. We hope our 137Cs deposition maps will help to coordinate decontamination efforts and plan regulatory measures in Japan. PMID:22084074

Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, And Caustic Wash Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 4 Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.; Fink, S. D.

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), and Caustic Wash Tank (CWT) samples from several of the ?microbatches? of Integrated Salt Disposition Project (ISDP) Salt Batch (?Macrobatch?) 4 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by inductively-coupled plasma emission spectroscopy (ICPES). Furthermore, samples from the CWT have been analyzed by a variety of methods to investigate a decline in the decontamination factor (DF) of the cesium observed at MCU. The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and themore » previous set of results for Macrobatch 3 samples indicate generally consistent operations. There is no indication of a disruption in plutonium and strontium removal. The average cesium DF and concentration factor (CF) for samples obtained from Macrobatch 4 are slightly lower than for Macrobatch 3, but still well within operating parameters. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in Actinide Removal Process (ARP).« less

Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

DOEpatents

Dietz, Mark L.; Horwitz, E. Philip; Bartsch, Richard A.; Barrans, Jr., Richard E.; Rausch, David

1999-01-01

A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution.

Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

DOEpatents

Dietz, M.L.; Horwitz, E.P.; Bartsch, R.A.; Barrans, R.E. Jr.; Rausch, D.

1999-03-30

A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution. 4 figs.

Particle-In-Cell Simulations of a Thermionic Converter

NASA Astrophysics Data System (ADS)

Clark, S. E.

2017-12-01

Simulations of thermionic converters are presented where cesium is used as a work function reducing agent in a nano-fabricated triode configuration. The cathode and anode are spaced on the order of 100 μm, and the grid structure has features on the micron scale near the anode. The hot side is operated near 1600 K, the cold side near 600 K, and the converter has the potential to convert heat to DC electrical current upwards of 20% efficiency. Affordable and robust thermionic converters have the potential to displace century old mechanical engines and turbines as a primary means of electrical power generation in the near future. High efficiency converters that operate at a small scale could be used to generate power locally and alleviate the need for large scale power transmission systems. Electron and negative cesium ion back emission from the anode are considered, as well as device longevity and fabrication feasibility.

Particle-In-Cell Simulations of a Thermionic Converter

NASA Astrophysics Data System (ADS)

Clark, Stephen

2017-10-01

Simulations of thermionic converters are presented where cesium is used as a work function reducing agent in a nano-fabricated triode configuration. The cathode and anode are spaced on the order of 100 μm, and the grid structure has features on the micron scale near the anode. The hot side is operated near 1600 K, the cold side near 600 K, and the converter has the potential to convert heat to DC electrical current upwards of 20% efficiency. Affordable and robust thermionic converters have the potential to displace century old mechanical engines and turbines as a primary means of electrical power generation in the near future. High efficiency converters that operate at a small scale could be used to generate power locally and alleviate the need for large scale power transmission systems. Electron and negative cesium ion back emission from the anode are considered, as well as device longevity and fabrication feasibility.

A comparative evaluation of IONSIV{reg_sign} IE-911 and chabazite zeolite for the removal of radiostrontium and cesium from wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bostick, D.T.; DePaoli, S.M.; Guo, B.

1998-11-01

Natural chabazite zeolite was selected as the baseline treatment technology for the removal of fission products, namely {sup 90}Sr and {sup 137}Cs, from near-neutral-pH process wastewater and groundwater. The sorbent IONSIV{reg_sign} IE-911, a crystalline silicotitanate manufactured by UOP, was recently tested in this capacity and found to compare extremely well against the baseline material. This paper presents and compares the results of similar batch and column tests performed using both materials, and summarizes the physical and chemical characteristics of the sorbents.

Ion exchange of Group I metals by hydrous crystalline silicotitanates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Z.; Philip, C.V.; Anthony, R.G.

1996-11-01

A new hydrous crystalline silicotitanate, labeled TAM-5 or CST, was developed for removing radioactive Cs{sup +} from aqueous nuclear waste. This material is stable to radiation, highly selective for cesium relative to sodium, potassium, rubidium, and protons, and performs well in acidic, neutral, and basic solutions. Various experiments were conducted to determine the ion exchange properties of TAM-5. Two kinds of ion exchange sites exist in the solid, and cation exchange in one site affects the ion exchange properties of the other site. These two types of sites have different thermal effects: with increasing temperature the pH of one increasesmore » and the pH of the other one decreases. The total ion exchange capacity is 4.6 mequiv/g, but the cesium ion exchange capacity was less, which shows that not all of the ion exchange sites are available for cesium exchange. Step changes were observed in the ion exchange isotherms. The solid phase behaved ideally prior to the step changes. The apparent capacities within the ideal solid region were 0.57 mequiv/g for Cs{sup +}, 1.18 mequiv/g for Rb{sup +}, and 1.2 mequiv/g for K{sup +}. Both direct competition by rubidium and protons and indirect competition by protons and potassium were observed. The rational selectivities, which were measured from binary ion exchange data, can be used in different solutions including the multicomponent ion exchange systems, because they are constant for an ideal solid. Binary ion exchange isotherms were also developed using the rational selectivity as the parameter for the isotherms of cesium, rubidinium, and potassium.« less

Characterization of Quantum Efficiency and Robustness of Cesium-Based Photocathodes

DTIC Science & Technology

2010-01-01

photocathodes produce picosecond-pulsed, high- current electron beams for photoinjection applications like free electron lasers . In photoinjectors, a...pulsed drive laser incident on the photocathode causes photoemission of short, dense bunches of electrons, which are then accelerated into a...relativistic, high quality beam. Future free electron lasers demand reliable photocathodes with long-lived quantum efficiency at suitable drive laser

Application of sorption technique for decontamination of liquid radwaste and natural water from cesium and strontium radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milyutin, V.V.; Gelis, V.M.; Penzin, R.A.

1995-12-31

In this paper the results obtained in field tests of decontaminating radioactive natural and industrial solutions of different chemical and radionuclide composition from cesium and strontium radionuclides are reported. Decontamination of industrial reservoir water at the Production Association Mayak (Chelyabinsk Region, Russia) was performed using CMP synthetic zeolite. Efficient decontamination of the feed water is achieved after preliminary precipitation of hardness salts in the form of carbonates. Decontamination of water from the pool for spent fuel element storage from {sup 137}Cs was conducted using NGA ferricyanide sorbent. Decontamination factors with respect to {sup 137}Cs of 400 have been reached, themore » installation throughput being 100,000 by (bed volumes). Decontamination of liquid radwaste at Murmansk Shipping Co was conducted with CFB, CMP synthetic zeolites and NGA ferricyanide sorbent as well. Decontamination of D and D solutions and wastes of the special laundry resulted in decontamination factors within the range of 20--400, 10--100, and 10--30 with respect to {sup 137}Cs, {sup 90}Sr, and total {beta}-activity, respectively. Installation throughput of 3,000--5,000 bv for zeolites and 8,000--10,000 bv for ferrocyanide sorbents has been reached. Results obtained prove the high efficiency of sorption technique for decontaminating solutions from cesium and strontium radionuclides.« less

Effect of kinetic energy on the doping efficiency of cesium cations into superfluid helium droplets

PubMed Central

Chen, Lei; Zhang, Jie; Freund, William M.; Kong, Wei

2015-01-01

We present an experimental investigation of the effect of kinetic energy on the ion doping efficiency of superfluid helium droplets using cesium cations from a thermionic emission source. The kinetic energy of Cs+ is controlled by the bias voltage of a collection grid collinearly arranged with the droplet beam. Efficient doping from ions with kinetic energies from 20 eV up to 480 V has been observed in different sized helium droplets. The relative ion doping efficiency is determined by both the kinetic energy of the ions and the average size of the droplet beam. At a fixed source temperature, the number of doped droplets increases with increasing grid voltage, while the relative ion doping efficiency decreases. This result implies that not all ions are captured upon encountering with a sufficiently large droplet, a deviation from the near unity doping efficiency for closed shell neutral molecules. We propose that this drop in ion doping efficiency with kinetic energy is related to the limited deceleration rate inside a helium droplet. When the source temperature changes from 14 K to 17 K, the relative ion doping efficiency decreases rapidly, perhaps due to the lack of viable sized droplets. The size distribution of the Cs+-doped droplet beam can be measured by deflection and by energy filtering. The observed doped droplet size is about 5 × 106 helium atoms when the source temperature is between 14 K and 17 K. PMID:26233132

Effect of kinetic energy on the doping efficiency of cesium cations into superfluid helium droplets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Lei; Zhang, Jie; Freund, William M.

We present an experimental investigation of the effect of kinetic energy on the ion doping efficiency of superfluid helium droplets using cesium cations from a thermionic emission source. The kinetic energy of Cs{sup +} is controlled by the bias voltage of a collection grid collinearly arranged with the droplet beam. Efficient doping from ions with kinetic energies from 20 eV up to 480 V has been observed in different sized helium droplets. The relative ion doping efficiency is determined by both the kinetic energy of the ions and the average size of the droplet beam. At a fixed source temperature,more » the number of doped droplets increases with increasing grid voltage, while the relative ion doping efficiency decreases. This result implies that not all ions are captured upon encountering with a sufficiently large droplet, a deviation from the near unity doping efficiency for closed shell neutral molecules. We propose that this drop in ion doping efficiency with kinetic energy is related to the limited deceleration rate inside a helium droplet. When the source temperature changes from 14 K to 17 K, the relative ion doping efficiency decreases rapidly, perhaps due to the lack of viable sized droplets. The size distribution of the Cs{sup +}-doped droplet beam can be measured by deflection and by energy filtering. The observed doped droplet size is about 5 × 10{sup 6} helium atoms when the source temperature is between 14 K and 17 K.« less

Effect of kinetic energy on the doping efficiency of cesium cations into superfluid helium droplets.

PubMed

Chen, Lei; Zhang, Jie; Freund, William M; Kong, Wei

2015-07-28

We present an experimental investigation of the effect of kinetic energy on the ion doping efficiency of superfluid helium droplets using cesium cations from a thermionic emission source. The kinetic energy of Cs(+) is controlled by the bias voltage of a collection grid collinearly arranged with the droplet beam. Efficient doping from ions with kinetic energies from 20 eV up to 480 V has been observed in different sized helium droplets. The relative ion doping efficiency is determined by both the kinetic energy of the ions and the average size of the droplet beam. At a fixed source temperature, the number of doped droplets increases with increasing grid voltage, while the relative ion doping efficiency decreases. This result implies that not all ions are captured upon encountering with a sufficiently large droplet, a deviation from the near unity doping efficiency for closed shell neutral molecules. We propose that this drop in ion doping efficiency with kinetic energy is related to the limited deceleration rate inside a helium droplet. When the source temperature changes from 14 K to 17 K, the relative ion doping efficiency decreases rapidly, perhaps due to the lack of viable sized droplets. The size distribution of the Cs(+)-doped droplet beam can be measured by deflection and by energy filtering. The observed doped droplet size is about 5 × 10(6) helium atoms when the source temperature is between 14 K and 17 K.

A review of the thermoelectronic laser energy converter (TELEC) program at Lewis Research Center

NASA Technical Reports Server (NTRS)

Alger, D. L.; Manista, E. J.; Thompson, R. W.

1978-01-01

The investigation of the Thermoelectronic Laser Energy Converter (TELEC) concept began with a feasibility study of a 1 megawatt sized TELEC system. The TELEC was to use either cesium vapor or hydrogen as the plasma medium. The cesium vapor TELEC appears to be the more practical device studied with an overall calculated conversion efficiency of greater than 48%. Following this study, a small TELEC cell was fabricated which demonstrated the conversion of a small amount of laser power to electrical power. The cell developed a short circuit current of 0.7 amperes and an open circuit voltage, as extrapolated from volt-ampere curves, of about 1.5 volts.

Evaluation and Testing of IONSIV IE-911 for the Removal of Cesium-137 from INEEL Tank Waste and Dissolved Calcines

DOE Office of Scientific and Technical Information (OSTI.GOV)

N. R. Mann; T. A. Todd; K. N. Brewer

1999-04-01

Development of waste treatment processes for the remediation of radioactive wastes is currently underway. A number of experiments were performed at the Idaho Nuclear Technology and Environmental Center (INTEC) located at the Idaho National Engineering and Environmental Laboratory (INEEL) with the commercially available sorbent material, IONSIV IE-911, crystalline silicotitanate (CST), manufactured by UOP LLC. The purpose of this work was to evaluate the removal efficiency, sorbent capacity and selectivity of CST for removing Cs-137 from actual and simulated acidic tank waste in addition to dissolved pilot-plant calcine solutions. The scope of this work included batch contact tests performed with non-radioactivemore » dissolved Al and Run-64 pilot plant calcines in addition to simulants representing the average composition of tank waste. Small-scale column tests were performed with actual INEEL tank WM-183 waste, tank waste simulant, dissolved Al and Run-64 pilot plant calcine solutions. Small-scale column experiments using actual WM-183 tank waste resulted in fifty-percent Cs-137 breakthrough at approximately 589 bed volumes. Small-scale column experiments using the tank waste simulant displayed fifty-percent Cs-137 breakthrough at approximately 700 bed volumes. Small-scale column experiments using dissolved Al calcine simulant displayed fifty-percent Cs-137 breakthrough at approximately 795 bed volumes. Column experiments with dissolved Run-64, pilot plant calcine did not reach fifty-percent breakthrough throughout the test.« less

PROCESSING ALTERNATIVES FOR DESTRUCTION OF TETRAPHENYLBORATE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambert, D; Thomas Peters, T; Samuel Fink, S

Two processes were chosen in the 1980's at the Savannah River Site (SRS) to decontaminate the soluble High Level Waste (HLW). The In Tank Precipitation (ITP) process (1,2) was developed at SRS for the removal of radioactive cesium and actinides from the soluble HLW. Sodium tetraphenylborate was added to the waste to precipitate cesium and monosodium titanate (MST) was added to adsorb actinides, primarily uranium and plutonium. Two products of this process were a low activity waste stream and a concentrated organic stream containing cesium tetraphenylborate and actinides adsorbed on monosodium titanate (MST). A copper catalyzed acid hydrolysis process wasmore » built to process (3, 4) the Tank 48H cesium tetraphenylborate waste in the SRS's Defense Waste Processing Facility (DWPF). Operation of the DWPF would have resulted in the production of benzene for incineration in SRS's Consolidated Incineration Facility. This process was abandoned together with the ITP process in 1998 due to high benzene in ITP caused by decomposition of excess sodium tetraphenylborate. Processing in ITP resulted in the production of approximately 1.0 million liters of HLW. SRS has chosen a solvent extraction process combined with adsorption of the actinides to decontaminate the soluble HLW stream (5). However, the waste in Tank 48H is incompatible with existing waste processing facilities. As a result, a processing facility is needed to disposition the HLW in Tank 48H. This paper will describe the process for searching for processing options by SRS task teams for the disposition of the waste in Tank 48H. In addition, attempts to develop a caustic hydrolysis process for in tank destruction of tetraphenylborate will be presented. Lastly, the development of both a caustic and acidic copper catalyzed peroxide oxidation process will be discussed.« less

METHOD OF PREPARING RADIOACTIVE CESIUM SOURCES

DOEpatents

Quinby, T.C.

1963-12-17

A method of preparing a cesium-containing radiation source with physical and chemical properties suitable for high-level use is presented. Finely divided silica is suspended in a solution containing cesium, normally the fission-product isotope cesium 137. Sodium tetraphenyl boron is then added to quantitatively precipitate the cesium. The cesium-containing precipitate is converted to borosilicate glass by heating to the melting point and cooling. Up to 60 weight percent cesium, with a resulting source activity of up to 21 curies per gram, is incorporated in the glass. (AEC)

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals.

PubMed

Zhang, Chengxi; Luan, Weiling; Yin, Yuhang; Yang, Fuqian

2017-01-01

Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX 3 , X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19-35 nm, high fluorescence quantum yield of 47.8-90.55%, and photoluminescence emission in the range of 450-700 nm. For the same precursor concentrations, the photoluminescence emission peak generally increases with increasing reaction temperature, revealing a controllable temperature effect on the photoluminescence characteristics of the synthesized nanocrystals. For quantum dots synthesized with a Br/I ratio of 1:3, a slight blue shift was observed for reaction temperatures greater than 100 °C. This PTFE-based microreactor system provides the unique capability of continuously synthesizing high-quality perovskite nanocrystals that emit over the full visible spectrum with applications ranging from displays and optoelectronic devices.

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals

PubMed Central

Zhang, Chengxi; Yin, Yuhang

2017-01-01

Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX3, X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19–35 nm, high fluorescence quantum yield of 47.8–90.55%, and photoluminescence emission in the range of 450–700 nm. For the same precursor concentrations, the photoluminescence emission peak generally increases with increasing reaction temperature, revealing a controllable temperature effect on the photoluminescence characteristics of the synthesized nanocrystals. For quantum dots synthesized with a Br/I ratio of 1:3, a slight blue shift was observed for reaction temperatures greater than 100 °C. This PTFE-based microreactor system provides the unique capability of continuously synthesizing high-quality perovskite nanocrystals that emit over the full visible spectrum with applications ranging from displays and optoelectronic devices. PMID:29259867

Photoluminescence and anti-deliquesce of cesium iodide and its sodium-doped films deposited by thermal evaporation at high deposition rates

NASA Astrophysics Data System (ADS)

Hsu, Jin-Cherng; Chiang, Yueh-Sheng; Ma, Yu-Sheng

2013-03-01

Cesium iodide (CsI) and sodium iodide (NaI) are good scintillators due to their high luminescence efficiency. These alkali halides can be excited by ultra-violet or by ionizing radiation. In this study, CsI and its Na-doped films about 8 μm thick were deposited by thermal evaporation boat without heating substrates at high deposition rates of 30, 50, 70, 90, and 110 nm/sec, respectively. The as-deposited films were sequentially deposited a silicon dioxide film to protect from deliquesce. And, the films were also post-annealed in vacuum at 150, 200, 250, and 300 °C, respectively. We calculated the packing densities of the samples according to the measurements of Fourier transform infrared spectroscopy (FTIR) and observed the luminescence properties by photoluminescence (PL) system. The surfaces and cross sections of the films were investigated by scanning electron microscope (SEM). From the above measurements we can find the optimal deposition rate of 90 nm/sec and post-annealing temperature of 250 °C in vacuum for the asdeposited cesium iodide and its sodium-doped films.

Mineral resource of the month: cesium

USGS Publications Warehouse

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.

Development of a Chemical Process for Production of Cesium Chloride from a Canadian Pollucite Ore

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parsons, H. W.; Vezina, J. A.; Simard, R.

1963-01-01

A chemical process was developed for the production of a high-purity cesium chioride from a pollucite (cesium aluminum silicate) ore from the Manitoba deposit of Chemalloy Minerais Ltd. The history of the deposit, and the present and possible future uses of cesium are briefly reviewed. Laboratory and piiot plant investigations on this ore have shown that a cyclic sulphuric acid leach followed by fractional crystallization will produce a rubidiumfree cesium alum, which can be converted to cesium chloride by thermal decomposition and ion exchange. On the basis of these findings it is concluded that the process is applicable to themore » tonnage production of cesium chloride. Reagent consumption was found to be 3.3 sulphuric acid and 0.3 lb hydrochloric acid per pound of cesium extracted. Overall extraction of cesium was 95 to 96%. (auth)« less

Wide Area Recovery and Resiliency Program (WARRP) Integrated Program Plan

DTIC Science & Technology

2011-06-01

Agent YELLOW, which is a mixture of the chemical warfare agents Sulfur Mustard and Lewisite, is a liquid with a garlic-like odor. Sulfur mustard...Radioisotope Background Cesium -137 (137Cs) is a radioactive isotope of cesium . The half-life of cesium -137 is 30.17 years. Because of the chemical...nature of cesium , it moves easily through the environment. This makes the cleanup of cesium - 137 difficult. People may ingest cesium -137 with food

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

NASA Astrophysics Data System (ADS)

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.

Fukushima Nuclear Crisis Recovery: A Modular Water Treatment System Deployed in Seven Weeks - 12489

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denton, Mark S.; Mertz, Joshua L.; Bostick, William D.

2012-07-01

On March 11, 2011, the magnitude 9.0 Great East Japan earthquake, Tohoku, hit off the Fukushima coast of Japan. This was one of the most powerful earthquakes in recorded history and the most powerful one known to have hit Japan. The ensuing tsunami devastated a huge area resulting in some 25,000 persons confirmed dead or missing. The perfect storm was complete when the tsunami then found the four reactor, Fukushima-Daiichi Nuclear Station directly in its destructive path. While recovery systems admirably survived the powerful earthquake, the seawater from the tsunami knocked the emergency cooling systems out and did extensive damagemore » to the plant and site. Subsequent hydrogen generation caused explosions which extended this damage to a new level and further flooded the buildings with highly contaminated water. Some 2 million people were evacuated from a fifty mile radius of the area and evaluation and cleanup began. Teams were assembled in Tokyo the first week of April to lay out potential plans for the immediate treatment of some 63 million gallons (a number which later exceeded 110 million gallons) of highly contaminated water to avoid overflow from the buildings as well as supply the desperately needed clean cooling water for the reactors. A system had to be deployed with a very brief cold shake down and hot startup before the rainy season started in early June. Joined by team members Toshiba (oil removal system), AREVA (chemical precipitation system) and Hitachi-GE (RO system), Kurion (cesium removal system following the oil separator) proposed, designed, fabricated, delivered and started up a one of a kind treatment skid and over 100 metric tons of specially engineered and modified Ion Specific Media (ISM) customized for this very challenging seawater/oil application, all in seven weeks. After a very short cold shake down, the system went into operation on June 17, 2011 on actual waste waters far exceeding 1 million Bq/mL in cesium and many other isotopes. One must remember that, in addition to attempting to do isotope removal in the competition of seawater (as high as 18,000 ppm sodium due to concentration), some 350,000 gallons of turbine oil was dispersed into the flooded buildings as well. The proposed system consisted of a 4 guard vessel skid for the oil and debris, 4 skids containing 16 cesium towers in a lead-lag layout with removable vessels (sent to an interim storage facility), and a 4 polishing vessel skid for iodine removal and trace cesium levels. At a flow rate of at least 220 gallons per minute, the system has routinely removed over 99% of the cesium, the main component of the activity, since going on line. To date, some 50% of the original activity has been removed and stabilized and cold shutdown of the plant was announced on December 10, 2011. In March and April alone, 10 cubic feet of Engineered Herschelite was shipped to Seabrook Nuclear Power Plant, NPP, to support the April 1, 2011 outage cleanup; 400 cubic feet was shipped to Oak Ridge National Laboratory (ORNL) for strontium (Sr-90) ground water remediation; and 6000 cubic feet (100 metric tons, MT, or 220,400 pounds) was readied for the Fukushima Nuclear Power Station with an additional 100 MT on standby for replacement vessels. This experience and accelerated media production in the U.S. bore direct application to what was to soon be used in Fukushima. How such a sophisticated and totally unique system and huge amount of media could be deployable in such a challenging and changing matrix, and in only seven weeks, is outlined in this paper as well as the system and operation itself. As demonstrated herein, all ten major steps leading up to the readiness and acceptance of a modular emergency technology recovery system were met and in a very short period of time, thus utilizing three decades of experience to produce and deliver such a system literally in seven weeks: - EPRI - U.S. Testing and Experience Leading to Introduction to EPRI - Japan and Subsequently TEPCO Emergency Meetings - Three Mile Island (TMI) Media and Vitrification Experience by PNNL - Commercial Nuclear Power Plant Media Experience (including long term Cs removal) - DOE Low Active Waste (LAW) and High Level Waste (HLW) in High Salt and pH Conditions Media and Vitrification Experience - National Laboratory (e.g. Oak Ridge National Laboratory, ORNL) Ground Water Media Experience - Gulf Oil Spill Media Experience in Seawater - All Media Had to be Fully Tested at High Rad Levels in Seawater and Oil Before Arriving in Japan - Final Waste Form and Disposal Experience (e.g., vitrification) - 100 Metric Tons (6000 cubic feet or 220,400 pounds) of Media had to be Immediately Available with the same amount in production as replacement media. [To date, for 2011, 400 MT of media have been prepared for Japan alone.] - Remote Operation, Modular Water Treatment Equipment Design and Fabrication in both Commercial NPP and DOE Canyon Operations. (authors)« less

Cesium vapor thermionic converter anomalies arising from negative ion emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rasor, Ned S., E-mail: ned.rasor@gmail.com

2016-08-14

Compelling experimental evidence is given that a longstanding limit encountered on cesium vapor thermionic energy converter performance improvement and other anomalies arise from thermionic emission of cesium negative ions. It is shown that the energy that characterizes thermionic emission of cesium negative ions is 1.38 eV and, understandably, is not the electron affinity 0.47 eV determined for the photodetachment threshold of the cesium negative ion. The experimental evidence includes measurements of collector work functions and volt-ampere characteristics in quasi-vacuum cesium vapor thermionic diodes, along with reinterpretation of the classic Taylor-Langmuir S-curve data on electron emission in cesium vapor. The quantitative effects ofmore » negative ion emission on performance in the ignited, unignited, and quasi-vacuum modes of cesium vapor thermionic converter operation are estimated.« less

Activities for the remediation of TEPCO's Fukushima Daiichi nuclear power plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinoshita, Hirofumi; Kometani, Yutaka; Asano, Takashi

2013-07-01

With the aim of fulfilling recovery work for the Fukushima Daiichi NPP, technological efforts have been made for the development of a survey robot system, adequate communication infrastructure technologies, high radiation environment compatible gamma cameras, heavy machinery-type robots (ASTACO-SoRa), remote decontamination devices (AROUNDER), and contaminated waste water treatment system. We have developed a new type of absorbents which remove cesium (Cs) and strontium (Sr) simultaneously at a high removal rate of 99 % or more. We will provide valuable solutions and rational systems for waste water treatment using this developed adsorbent as well as other various adsorbents for the recoverymore » of Fukushima Daiichi NPP.« less

Fission product transport analysis in a loss of decay heat removal accident at Browns Ferry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wichner, R.P.; Weber, C.F.; Hodge, S.A.

1984-01-01

This paper summarizes an analysis of the movement of noble gases, iodine, and cesium fission products within the Mark-I containment BWR reactor system represented by Browns Ferry Unit 1 during a postulated accident sequence initiated by a loss of decay heat removal (DHR) capability following a scram. The event analysis showed that this accident could be brought under control by various means, but the sequence with no operator action ultimately leads to containment (drywell) failure followed by loss of water from the reactor vessel, core degradation due to overheating, and reactor vessel failure with attendant movement of core debris ontomore » the drywell floor.« less

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

DOE PAGES

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene; ...

2016-02-06

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

Performance and modeling of cesium ion exchange by ENGI neered form crystalline silicotitanates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthony, R.G.; Gu, D.; Huckman, M.

1996-10-01

TAM-5, a hydrous crystalline silicotitanate (CST) powder developed by Sandia National Laboratories and Texas A&M University, and commercialized by UOP as IONSIV{reg_sign} Ion Exchanger Type IE-910, is a highly selective material for removing cesium and strontium from aqueous radioactive wastes such as those found at the Hanford site in Washington. An engineered form of the material suitable for column ion exchange type operations has been developed and tested. Data relevant to processing radioactive tank wastes including equilibrium distribution coefficients and column testing will be presented. The impact of exposure of the engineered form to chemically aggressive environments such as itmore » might experience during waste processing, and to the less aggressive environments it might experience during post processing storage has been assessed. The thermal stability of the material has also been evaluated. The experimental results have been integrated with an effort to model the material`s equilibrium and kinetic behavior.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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.« less

Radionuclide Basics: Cesium-137

EPA Pesticide Factsheets

The most common radioactive form of cesium (chemical symbol Cs) is Cesium-137. Cesium-137 is produced by nuclear fission for use in medical devices and gauges and is one of the byproducts of nuclear fission in nuclear reactors and nuclear weapons testing.

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

PubMed

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 but is strongly related to structural changes in the clay minerals in the suspended particles. Hydrated Na + ions expand the interlayer distance of the clay minerals, resulting in the facile desorption of cesium; in contrast, dehydrated K + ions reduce the interlayer distance and inhibit the desorption of cesium. In conclusion, the desorption of cesium from the suspended particles is controlled by the presence of sodium and potassium ions and the preloaded cesium concentration in the suspended particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solar sustained plasma/absorber conceptual design

NASA Technical Reports Server (NTRS)

Rodgers, R. J.; Krascella, N. L.; Kendall, J. S.

1979-01-01

A space power system concept was evaluated which uses concentrated solar energy to heat a working fluid to temperatures as high as 4000 K. The high temperature working fluid could be used for efficient electric power production in advanced thermal or magnetohydrodynamic conversion cycles. Energy absorber configurations utilizing particles or cesium vapor absorber material were investigaed. Results of detailed radiant heat transfer calculations indicated approximately 86 percent of the incident solar energy could be absorbed within a 12-cm-dia flowing stream of gas borne carbon particles. Calculated total energy absorption in the cesium vapor seeded absorber configuration ranged from 34 percent to 64 percent of the incident solar energy. Solar flux concentration ratios of between approximately 3000 and 10,000 will be required to sustain absorber temperatures in the range from 3000 K to 4000 K.

Highly luminescent colloidal nanoplates of perovskite cesium lead halide and their oriented assemblies

DOE PAGES

Bekenstein, Yehonadav; Koscher, Brent A.; Eaton, Samuel W.; ...

2015-12-15

Anisotropic colloidal quasi-two-dimensional nanoplates (NPLs) hold great promise as functional materials due to their combination of low dimensional optoelectronic properties and versatility through colloidal synthesis. Recently, lead-halide perovskites have emerged as important optoelectronic materials with excellent efficiencies in photovoltaic and light-emitting applications. Here we report the synthesis of quantum confined all inorganic cesium lead halide nanoplates in the perovskite crystal structure that are also highly luminescent (PLQY 84%). The controllable self-assembly of nanoplates either into stacked columnar phases or crystallographic-oriented thin-sheet structures is demonstrated. Furthermore, the broad accessible emission range, high native quantum yields, and ease of self-assembly make perovskitemore » NPLs an ideal platform for fundamental optoelectronic studies and the investigation of future devices.« less

Composition-Graded Cesium Lead Halide Perovskite Nanowires with Tunable Dual-Color Lasing Performance.

PubMed

Huang, Ling; Gao, Qinggang; Sun, Ling-Dong; Dong, Hao; Shi, Shuo; Cai, Tong; Liao, Qing; Yan, Chun-Hua

2018-05-21

Cesium lead halide (CsPbX 3 ) perovskite has emerged as a promising low-threshold multicolor laser material; however, realizing wavelength-tunable lasing output from a single CsPbX 3 nanostructure is still constrained by integrating different composition. Here, the direct synthesis of composition-graded CsPbBr x I 3- x nanowires (NWs) is reported through vapor-phase epitaxial growth on mica. The graded composition along the NW, with an increased Br/I from the center to the ends, comes from desynchronized deposition of cesium lead halides and temperature-controlled anion-exchange reaction. The graded composition results in varied bandgaps along the NW, which induce a blueshifted emission from the center to the ends. As an efficient gain media, the nanowire exerts position-dependent lasing performance, with a different color at the ends and center respectively above the threshold. Meanwhile, dual-color lasing with a wavelength separation of 35 nm is activated simultaneously at a site with an intermediate composition. This position-dependent dual-color lasing from a single nanowire makes these metal halide perovskites promising for applications in nanoscale optical devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2012 CFR

2012-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2014 CFR

2014-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2013 CFR

2013-01-01

...-126 .1 .001 Iodine-129 .1 .01 Iodine-131 .1 .001 Iodine-132 10 .1 Iodine-133 1 .01 Iodine-134 10 .1...-125 1 .01 Arsenic-73 10 .1 Arsenic-74 1 .01 Arsenic-76 1 .01 Arsenic-77 10 .1 Barium-131 10 .1 Barium... Cerium-144 .1 .001 Cesium-131 100 1. Cesium-134m 100 1. Cesium-134 .1 .001 Cesium-135 1 .01 Cesium-136 10...

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed CARIBU radioactive beams at ATLAS, is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The offline charge breeding tests are being performed using a surface ionization source that produces singly-charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition ratemore » and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20±0.7)% breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demmer, Rick; Boxall, Colin

Radiological decontamination is an essential enterprise that has become more important over the last four decades due to unfortunate accidents and the threat of terrorist actions. Decontamination can be an effective, beneficial alternative for the cleanup of radiological contamination events; however, the costs and benefits need to be balanced against those for complete removal and demolition of contaminated areas or facilities. Demolition and removal are often the first options considered in such circumstances as decontamination may be thought of as slow and costly. Decontamination has advantages, including significant waste reduction over demolition. In areas with buildings of cultural or societalmore » importance, demolition may not be an option. Three decontamination evaluation test series are the focus of this article: SIMCON 1 and 2 (i.e., simulated contamination), and Urban RDD (radiological dispersal device, i.e., a dirty bomb detonation). These test series revealed that different contaminants respond differently during decontamination. This was found to be true with both SIMCON and Urban RDD simulant tests. SIMCON 2 especially demonstrated that chemically different contaminants respond differently to different decontamination methods: cesium appears to be less tenacious (more easily removed) than zirconium using chemical methods. These differences were underscored by the Urban RDD tests where americium and cobalt tended to precipitate on high pH surfaces (such as concrete), making them easier to remove, while cesium and strontium were essentially unaffected by surface pH and were imbibed more strongly into the substrate pore structure. While authorities argue over the contributions of contaminant chemistry and substrate morphology, the clear answer is that each has a contribution to the tenacity of a contaminant. Knowing how these characteristics interact will make us better at decontamination in the field. This knowledge refutes the efforts of perhaps well-meaning marketers to define our decontamination problems by what products they are trying to sell; often a “one size fits all” type approach. Knowing even a little bit about the character of the decontamination problem will save time and money and increase the efficacy of decontamination.« less

Slow hot carrier cooling in cesium lead iodide perovskites

NASA Astrophysics Data System (ADS)

Shen, Qing; Ripolles, Teresa S.; Even, Jacky; Ogomi, Yuhei; Nishinaka, Koji; Izuishi, Takuya; Nakazawa, Naoki; Zhang, Yaohong; Ding, Chao; Liu, Feng; Toyoda, Taro; Yoshino, Kenji; Minemoto, Takashi; Katayama, Kenji; Hayase, Shuzi

2017-10-01

Lead halide perovskites are attracting a great deal of interest for optoelectronic applications such as solar cells, LEDs, and lasers because of their unique properties. In solar cells, heat dissipation by hot carriers results in a major energy loss channel responsible for the Shockley-Queisser efficiency limit. Hot carrier solar cells offer the possibility to overcome this limit and achieve energy conversion efficiency as high as 66% by extracting hot carriers. Therefore, fundamental studies on hot carrier relaxation dynamics in lead halide perovskites are important. Here, we elucidated the hot carrier cooling dynamics in all-inorganic cesium lead iodide (CsPbI3) perovskite using transient absorption spectroscopy. We observe that the hot carrier cooling rate in CsPbI3 decreases as the fluence of the pump light increases and the cooling is as slow as a few 10 ps when the photoexcited carrier density is 7 × 1018 cm-3, which is attributed to phonon bottleneck for high photoexcited carrier densities. Our findings suggest that CsPbI3 has a potential for hot carrier solar cell applications.

Selection of an anti-solvent for efficient and stable cesium-containing triple cation planar perovskite solar cells.

PubMed

Xiao, Meng; Zhao, Li; Geng, Min; Li, Yanyan; Dong, Binghai; Xu, Zuxun; Wan, Li; Li, Wenlu; Wang, Shimin

2018-06-19

The perovskite layer is a crucial component influencing high-performance perovskite solar cells (PSCs). In the one-step solution method, anti-solvents are important for obtaining smooth and uniform perovskite active layers. This work explored the effect of various anti-solvents on the preparation of triple cation perovskite active layers. In general, anti-solvents with low dielectric constants, low polarity, and low boiling point are suitable for the preparation of perovskite films. Microstructural and elemental analyses of the perovskite films were systematically conducted by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The photoelectric properties, carrier transfer, and recombination process in the PSCs were investigated using photocurrent-voltage characteristic curves and electrochemical impedance spectroscopy. Optimum performance was obtained when the anti-solvent was diethyl ether (DEE) and the ratio of the optimum amount of DEE to the volume of the precursor was 1 : 10. Meanwhile, we found that the partial replacement of formamidinium/methylammonium by cesium could increase the stability of the PSCs and enhance the power conversion efficiency from 15.49% to over 17.38%.

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

DOEpatents

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.

Method for primary containment of cesium wastes

DOEpatents

Angelini, Peter; Lackey, Walter J.; Stinton, David P.; Blanco, Raymond E.; Bond, Walter D.; Arnold, Jr., Wesley D.

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.degree. 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.degree. C. for a suitable duration.

Development of a universal solvent for the decontamination of acidic liquid radioactive wastes

NASA Astrophysics Data System (ADS)

Todd, T. A.; Brewer, K. N.; Law, J. D.; Wood, D. J.; Herbest, R. S.; Romanovskiy, V. N.; Esimantovskiy, V. M.; Smirnov, I. V.; Babain, V. A.

1999-01-01

A teritiary solvent containing chlorinated cobalt dicarbollide, polyethylene glycol and diphenylcarbamoylmethylphosphine oxide was evaluated in different non-nitroaromatic diluents for the separation of cesium, strontium, actinides and rare earth elements from acidic liquid radioactive waste. Decontamination factors of >95% for Cs, 99.7% for Sr, and 99.99% for actinides were achieved in four successive batch contacts using actual radioactive waste. Pilot plant testing in centrifugal contactors using simulated wastes, has demonstrated removal of >99% of all targeted ions.

Evaluation of ambient dose equivalent rates influenced by vertical and horizontal distribution of radioactive cesium in soil in Fukushima Prefecture.

PubMed

Malins, Alex; Kurikami, Hiroshi; Nakama, Shigeo; Saito, Tatsuo; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

2016-01-01

The air dose rate in an environment contaminated with (134)Cs and (137)Cs depends on the amount, depth profile and horizontal distribution of these contaminants within the ground. This paper introduces and verifies a tool that models these variables and calculates ambient dose equivalent rates at 1 m above the ground. Good correlation is found between predicted dose rates and dose rates measured with survey meters in Fukushima Prefecture in areas contaminated with radiocesium from the Fukushima Dai-ichi Nuclear Power Plant accident. This finding is insensitive to the choice for modeling the activity depth distribution in the ground using activity measurements of collected soil layers, or by using exponential and hyperbolic secant fits to the measurement data. Better predictions are obtained by modeling the horizontal distribution of radioactive cesium across an area if multiple soil samples are available, as opposed to assuming a spatially homogeneous contamination distribution. Reductions seen in air dose rates above flat, undisturbed fields in Fukushima Prefecture are consistent with decrement by radioactive decay and downward migration of cesium into soil. Analysis of remediation strategies for farmland soils confirmed that topsoil removal and interchanging a topsoil layer with a subsoil layer result in similar reductions in the air dose rate. These two strategies are more effective than reverse tillage to invert and mix the topsoil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Photocathode transfer and storage techniques using alkali vapor feedback control

NASA Astrophysics Data System (ADS)

Springer, R. W.; Cameron, B. J.

1991-12-01

Photocathodes of quantum efficiency above 1 percent at the doubled YAG frequency of 532 nM are very sensitive to the local vacuum environment. These cathodes must have a band gap of less than 2.3 eV, and a work function that is also on the order of approximately 2 volts or less. As such, these surfaces are very reactive as they provide many surface states for the residual gases that have positive electron affinities such as oxygen and omnipotent water. Attendant to this problem is that the optimal operating point for some of these cesium based cathodes is unstable. Three of the cesium series were tried, the Cs-Ag-Bi-O, the Cs3Sb and the K2CsSb. The most stable material found is the K2CsSb. The vacuum conditions can be met by a variety of pumping schemes. The vacuum is achieved by using sputter ion diode pumps, and baking at 250 C or less for whatever time is required to reduce the pump currents to below 1 uA at room temperature. To obtain the required partial pressure of cesium, a simple very sensitive diagnostic gauge has been developed that can discriminate between free alkali and other gases present. This Pressure Alkali Monitor (PAM) can be used on cesium sources to provide a low partial pressure using standard feedback techniques. Photocathodes of arbitrary composition have been transferred to a separate vacuum system and preserved for over 10 days with less than a 25 percent loss to the QE at 543.5 nM.

Process for cesium decontamination and immobilization

DOEpatents

Komarneni, Sridhar; Roy, Rustum

1989-01-01

Cesium can be selectively recovered from a nuclear waste solution containing cesium together with other metal ions by contact with a modified phlogopite which is a hydrated, sodium phlogopite mica. Once the cesium has entered the modified phlogopite it is fixed and can be safely stored for long periods of time.

Biomass Potential of Virgin and Calcined Tapioca (Cassava Starch) for the Removal of Sr(II) and Cs(I) from Aqueous Solutions.

PubMed

Ogata, Fumihiko; Nagai, Noriaki; Ueta, Erimi; Nakamura, Takehiro; Kawasaki, Naohito

2018-01-01

In this study, we prepared novel adsorbents containing virgin and calcined tapioca products for removing strontium (Sr(II)) and cesium (Cs(I)) from aqueous solutions. The characteristics of tapioca, along with its capacity to adsorb Sr(II) and Cs(I), were evaluated. Multiple tapioca products were prepared and tested. The adsorbent prepared by boiling the tapioca followed by calcination at 300°C (BTP300) was the most effective. In addition, adsorption was affected by the adsorbent's surface properties. The Sr(II) and Cs(I) adsorbed onto BTP300 could be recovered through desorption by hydrochloric acid at different concentrations, which indicates that BTP300 can be used several times for adsorption/desorption. The results of this study suggest that BTP300, which was produced from tapioca biomass, can remove Sr(II) and Cs(I) from aqueous solutions.

Cesium Sorption/Desorption Experiments with IONSIV(R) IE-911 in Radioactive Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, D.D.

2001-02-13

This report describes cesium desorption from IONSIV IE-911 during ambient temperature storage and following temperature increases to 35 and 55 degrees C. This report also describes cesium sorption following return to ambient temperature. The IONSIV IE-911 used in these tests was loaded with cesium from Tank 44F radioactive waste in an ion exchange column test in 1999. Cesium desorbed and resorbed in the presence of Tank 44F waste and simulated waste solutions.

Long Duration Responses in Squid Giant Axons Injected with 134Cesium Sulfate Solutions

PubMed Central

Sjodin, R. A.

1966-01-01

Giant axons from the squid were injected with 1.5 M cesium sulfate solutions containing the radioactive isotopes 42K and 134Cs. These axons, when stimulated, gave characteristic long duration action potentials lasting between 5 and 45 msec. The effluxes of 42K and 134Cs were measured both under resting conditions and during periods of repetitive stimulation. During the lengthened responses there were considerable increases in potassium efflux but only small increases in cesium efflux. The selectivity of the delayed rectification process was about 9 times greater for potassium ions than for cesium ions. The data suggest that internal cesium ions inhibit the outward potassium movement occurring during an action potential. The extra potassium effluxes taking place during excitation appear to be reduced in the presence of cesium ions to values between 7 and 22% of those expected in the absence of cesium inhibition. PMID:11526828

Process for cesium decontamination and immobilization

DOEpatents

Komarneni, S.; Roy, R.

1988-04-25

Cesium can be selectively recovered from a nuclear waste solution containing cesium together with other metal ions by contact with a modified phlogopite which is a hydrated, sodium phlogopite mica. Once the cesium has entered the modified phlogopite it is fixed and can be safely stored for long periods of time. 6 figs., 2 tabs.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1979-01-01

A surface ionization gauge (SIG) was constructed and used to measure the Cs/sup 0/ flow rate through the emission slit of a surface-plasma source (SPS) of H/sup -/ ions with Penning geometry. The equivalent cesium density in the SPS discharge is deduced from these flow measurements. For dc operation the optimum H/sup -/ current occurs at an equivalent cesium density of approx. 7 x 10/sup 12/ cm/sup -3/ (corresponding to an average cesium consumption rate of 0.5 mg/h). For pulsed operation the optimum H/sup -/ current occurs at an equivalent cesium density of approx. 2 x 10/sup 13/ cm/sup -3/more » (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.« less

Re-suspension of Cesium-134/137 into the Canadian Environment and the Contribution Stemming from the Fukushima-Daiichi Nuclear Incident

NASA Astrophysics Data System (ADS)

Mercier, Jean-Francois; Zhang, Weihua; Loignon-Houle, Francis; Cooke, Michael W.; Ungar, Kurt R.; Pellerin, Eric R.

2013-04-01

Cesium-137 (t1/2 = 30 yr) and cesium-134 (t1/2 = 2yr) constitute major fission by-products observed as the result of a nuclear incident. Such radioisotopes become integrated into the soil and biomass, and can therefore undergo re-suspension into the environment via activities such as forest fires. The Canadian Radiological Monitoring Network (CRMN), which consists of 26 environmental monitoring stations spread across the country, commonly observes cesium-137 in air filters due to re-suspension of material originating from long-past weapons testing. Cesium-134 is not observed owing to its relatively short half-life. The Fukushima-Daiichi nuclear power plant incident of March 2011 caused a major release of radioactive materials into the environment. In Canada, small quantities of both cesium-137 and cesium-134 fallout were detected with great frequency in the weeks which followed, falling off rapidly beginning in July 2011. Since September 2011, the CRMN has detected both cesium-137 and cesium-134 from air filters collected at Yellowknife, Resolute, and Quebec City locations. Using the known initial cesium-134/cesium-137 ratio stemming from this incident, along with a statistical assessment of the normality of the data distribution, we herein present evidence that strongly suggests that these activity spikes are due to re-suspended hot particles originating from the Fukushima-Daiichi nuclear power plant incident. Moreover, we have evidence to suggest that this re-suspension is localized in nature. This study provided empirical insight into the transport and uptake of radionuclides over vast distances, and it demonstrates that the CRMN was able to detect evidence of a re-suspension of Fukushima-Daiichi related isotopes.

Cesium Uptake by Rice Roots Largely Depends Upon a Single Gene, HAK1, Which Encodes a Potassium Transporter.

PubMed

Rai, Hiroki; Yokoyama, Saki; Satoh-Nagasawa, Namiko; Furukawa, Jun; Nomi, Takiko; Ito, Yasuka; Fujimura, Shigeto; Takahashi, Hidekazu; Suzuki, Ryuichiro; Yousra, ELMannai; Goto, Akitoshi; Fuji, Shinichi; Nakamura, Shin-Ichi; Shinano, Takuro; Nagasawa, Nobuhiro; Wabiko, Hiroetsu; Hattori, Hiroyuki

2017-09-01

Incidents at the Fukushima and Chernobyl nuclear power stations have resulted in widespread environmental contamination by radioactive nuclides. Among them, 137cesium has a 30 year half-life, and its persistence in soil raises serious food security issues. It is therefore important to prevent plants, especially crop plants, from absorbing radiocesium. In Arabidopsis thaliana, cesium ions are transported into root cells by several different potassium transporters such as high-affinity K+ transporter 5 (AtHAK5). Therefore, the cesium uptake pathway is thought to be highly redundant, making it difficult to develop plants with low cesium uptake. Here, we isolated rice mutants with low cesium uptake and reveal that the Oryza sativa potassium transporter OsHAK1, which is expressed on the surfaces of roots, is the main route of cesium influx into rice plants, especially in low potassium conditions. During hydroponic cultivation with low to normal potassium concentrations (0-206 µM: the normal potassium level in soil), cesium influx in OsHAK1-knockout lines was no greater than one-eighth that in the wild type. In field experiments, knockout lines of O. sativa HAK1 (OsHAK1) showed dramatically reduced cesium concentrations in grains and shoots, but their potassium uptake was not greatly affected and their grain yields were similar to that of the wild type. Our results demonstrate that, in rice roots, potassium transport systems other than OsHAK1 make little or no contribution to cesium uptake. These results show that low cesium uptake rice lines can be developed for cultivation in radiocesium-contaminated areas. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Method for synthesizing pollucite from chabazite and cesium chloride

DOEpatents

Pereira, C.

1999-02-23

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.

Method for synthesizing pollucite from chabazite and cesium chloride

DOEpatents

Pereira, Candido

1999-01-01

A method for immobilizing waste chlorides salts containing radionuclides and hazardous nuclear material for permanent disposal, and in particular, a method 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.degree. 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.

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE PAGES

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; ...

2015-08-28

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostroumov, P. N., E-mail: ostroumov@anl.gov; Barcikowski, A.; Dickerson, C. A.

The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

Pretreatment of Hanford medium-curie wastes by fractional crystallization.

PubMed

Nassif, Laurent; Dumont, George; Alysouri, Hatem; Rousseau, Ronald W

2008-07-01

Acceleration of the schedule for decontamination of the Hanford site using bulk vitrification requires implementation of a pretreatment operation. Medium-curie waste must be separated into two fractions: one is to go to a waste treatment and immobilization plant and a second, which is low-activity waste, is to be processed by bulk vitrification. The work described here reports research on using fractional crystallization for that pretreatment. Sodium salts are crystallized by evaporation of water from solutions simulating those removed from single-shell tanks, while leaving cesium in solution. The crystalline products are then recovered and qualified as low-activity waste, which is suitable upon redissolution for processing by bulk vitrification. The experimental program used semibatch operation in which a feed solution was continuously added to maintain a constant level in the crystallizer while evaporating water. The slurry recovered at the end of a run was filtered to recover product crystals, which were then analyzed to determine their composition. The results demonstrated that targets on cesium separation from the solids, fractional recovery of sodium salts, and sulfate content of the recovered salts can be achieved by the process tested.

Application Status of Rubidium, Cesium and Research Situation of its Separation from Brine with Solvent Extraction

NASA Astrophysics Data System (ADS)

Shi, Zhen; Du, Xuemin; Wang, Shiqiang; Guo, Yafei; Deng, Tianlong

2017-12-01

Rubidium, cesium and its compounds play an important role in traditional and high-tech fields. This paper focuses on the research status of separation rubidium and cesium in brine using solvent extraction, and briefly introduced the characteristics of this method, which can be used to realize industrial production of rubidium and cesium from brine.

Forcing Cesium into Higher Oxidation States Using Useful hard x-ray Induced Chemistry under High Pressure

NASA Astrophysics Data System (ADS)

Sneed, D.; Pravica, M.; Kim, E.; Chen, N.; Park, C.; White, M.

2017-10-01

This paper discusses our attempt to synthesize higher oxidation forms of cesium fluoride by pressurizing cesium fluoride in a fluorine-rich environment created via the x-ray decomposition of potassium tetrafluoroborate. This was done in order to confirm recent theoretical predictions of higher oxidation forms of CsFn. We discuss the development of a technique to produce molecular fluorine in situ via useful hard x-ray photochemistry, and the attempt to utilize this technique to form higher oxidation states of cesium fluoride. In order to verify the formation of the novel stoichiometric species of CsFn. X-ray Absorption Near Edge Spectroscopy (XANES) centered on the cesium K-edge was performed to probe the oxidation state of cesium as well as the local molecular coordination around Cs.

Hepatic uptake and biliary excretion of manganese in the little skate, Leucoraja erinacea.

PubMed

Madejczyk, Michael S; Boyer, James L; Ballatori, Nazzareno

2009-05-01

The liver is a major organ involved in regulating whole body manganese (Mn) homeostasis; however, the mechanisms of Mn transport across the hepatocyte basolateral and canalicular membranes remain poorly defined. To gain insight into these transport steps, the present study measured hepatic uptake and biliary excretion of Mn in an evolutionarily primitive marine vertebrate, the elasmobranch Leucoraja erinacea, the little skate. Mn was rapidly removed from the recirculating perfusate of isolated perfused skate livers in a dose-dependent fashion; however, only a small fraction was released into bile (<2% in 6 h). Mn was also rapidly taken up by freshly isolated skate hepatocytes in culture. Mn uptake was inhibited by a variety of divalent metals, but not by cesium. Analysis of the concentration-dependence of Mn uptake revealed of two components, with apparent K(m) values 1.1+/-0.1 microM and 112+/-29 microM. The K(m) value for the high-affinity component was similar to the measured skate blood Mn concentration, 1.9+/-0.5 microM. Mn uptake was reduced by nearly half when bicarbonate was removed from the culture medium, but was unaffected by a change in pH from 6.5 to 8.5, or by substitution of Na with Li or K. Mn efflux from the hepatocytes was also rapid, and was inhibited when cells were treated with 0.5 mM 2,4-dinitrophenol to deplete ATP levels. These data indicate that skate liver has efficient mechanisms for removing Mn from the sinusoidal circulation, whereas overall biliary excretion is low and appears to be mediated in part by an ATP-sensitive mechanism.

Hepatic uptake and biliary excretion of manganese in the little skate, Leucoraja erinacea

PubMed Central

Madejczyk, Michael S.; Boyer, James L.; Ballatori, Nazzareno

2008-01-01

The liver is a major organ involved in regulating whole body manganese (Mn) homeostasis; however, the mechanisms of Mn transport across the hepatocyte basolateral and canalicular membranes remain poorly defined. To gain insight into these transport steps, the present study measured hepatic uptake and biliary excretion of Mn in an evolutionarily primitive marine vertebrate, the elasmobranch Leucoraja erinacea, the little skate. Mn was rapidly removed from the recirculating perfusate of isolated perfused skate livers in a dose-dependent fashion; however, only a small fraction was released into bile (<2% in 7h). Mn was also rapidly taken up by freshly isolated skate hepatocytes in culture. Mn uptake was inhibited by a variety of divalent metals, but not by cesium. Analysis of the concentration-dependence of Mn uptake revealed of two components, with apparent Km values 1.1 ± 0.1 μM and 112 ± 29 μM. The Km value for the high-affinity component was similar to the measured skate blood Mn concentration, 1.9 ± 0.5 μM. Mn uptake was reduced by nearly half when bicarbonate was removed from the culture medium, but was unaffected by a change in pH from 6.5 to 8.5, or by substitution of Na with Li or K. Mn efflux from the hepatocytes was also rapid, and was inhibited when cells were treated with 0.5 mM 2,4-dinitrophenol to deplete ATP levels. These data indicate that skate liver has efficient mechanisms for removing Mn from the sinusoidal circulation, whereas overall biliary excretion is low and appears to be mediated in part by an ATP-sensitive mechanism. PMID:19141331

Thermionic photovoltaic energy converter

NASA Technical Reports Server (NTRS)

Chubb, D. L. (Inventor)

1985-01-01

A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

Stable and radioactive cesium: A review about distribution in the environment, uptake and translocation in plants, plant reactions and plants' potential for bioremediation.

PubMed

Burger, Anna; Lichtscheidl, Irene

2018-03-15

Radiocesium in water, soil, and air represents a severe threat to human health and the environment. It either acts directly on living organisms from external sources, or it becomes incorporated through the food chain, or both. Plants are at the base of the food chain; it is therefore essential to understand the mechanisms of plants for cesium retention and uptake. In this review we summarize investigations about sources of stable and radioactive cesium in the environment and harmful effects caused by internal and external exposure of plants to radiocesium. Uptake of cesium into cells occurs through molecular mechanisms such as potassium and calcium transporters in the plasma membrane. In soil, bioavailability of cesium depends on the chemical composition of the soil and physical factors such as pH, temperature and tilling as well as on environmental factors such as soil microorganisms. Uptake of cesium occurs also from air through interception and absorption on leaves and from water through the whole submerged surface. We reviewed information about reducing cesium in the vegetation by loss processes, and we extracted transfer factors from the available literature and give an overview over the uptake capacities of 72 plants for cesium from the substratum to the biomass. Plants with high uptake potential could be used to remediate soil and water from radiocesium by accumulation and rhizofiltration. Inside plants, cesium distributes fast between the different plant organs and cells, but cesium in soil is extremely stable and remains for decades in the rhizosphere. Monitoring of contaminated soil therefore has to continue for many decades, and edible plants grown on such soil must continuously be monitored. Copyright © 2017 Elsevier B.V. All rights reserved.

Negative ion beam injection apparatus with magnetic shield and electron removal means

DOEpatents

Anderson, Oscar A.; Chan, Chun F.; Leung, Ka-Ngo

1994-01-01

A negative ion source is constructed to produce H.sup.- ions without using Cesium. A high percentage of secondary electrons that typically accompany the extracted H.sup.- are trapped and eliminated from the beam by permanent magnets in the initial stage of acceleration. Penetration of the magnetic field from the permanent magnets into the ion source is minimized. This reduces the destructive effect the magnetic field could have on negative ion production and extraction from the source. A beam expansion section in the extractor results in a strongly converged final beam.

Process for preparing chemically modified micas for removal of cesium salts from aqueous solution

DOEpatents

Yates, Stephen Frederic; DeFilippi, Irene; Gaita, Romulus; Clearfield, Abraham; Bortun, Lyudmila; Bortun, Anatoly

2000-09-05

A chemically modified mica composite formed by heating a trioctahedral mica in an aqueous solution of sodium chloride having a concentration of at least 1 mole/liter at a temperature greater than 180 degrees Centigrade for at least 20 hours, thereby replacing exchangeable ions in the mica with sodium. Formation is accomplished at temperatures and pressures which are easily accessed by industrial equipment. The reagent employed is inexpensive and non-hazardous, and generates a precipitate which is readily separated from the modified mica.

Growth and cesium uptake responses of Phytolacca americana Linn. and Amaranthus cruentus L. grown on cesium contaminated soil to elevated CO2 or inoculation with a plant growth promoting rhizobacterium Burkholderia sp. D54, or in combination.

PubMed

Tang, Shirong; Liao, Shangqiang; Guo, Junkang; Song, Zhengguo; Wang, Ruigang; Zhou, Xiaomin

2011-12-30

Growth and cesium uptake responses of plants to elevated CO(2) and microbial inoculation, alone or in combination, can be explored for clean-up of contaminated soils, and this induced phytoextraction may be better than the natural process. The present study used open-top chambers to investigate combined effects of Burkholderia sp. D54 inoculation and elevated CO(2) (860 μL L(-1)) on growth and Cs uptake by Phytolacca americana and Amaranthus cruentus grown on soil spiked with various levels of Cs (0-1000 mg kg(-1)). Elevated CO(2) and bacterial inoculation, alone or in combination, significantly increased biomass production with increased magnitude, ranging from 22% to 139% for P. americana, and 14% to 254% for A. cruentus. Total tissue Cs in both plants was significantly greater for bacterial inoculation treatment singly, and combined treatments of bacterial inoculation and elevated CO(2) than for the control treatment in most cases. Regardless of CO(2) concentrations and bacterial inoculation, A. cruentus had higher tissue Cs concentration, Cs transfer factors and concentration ratios than P. americana, but they had slightly different contents of antioxidant enzymes. It is concluded that combined effects of elevated CO(2) and microbial inoculation with regard to plant ability to grow and remove radionuclides from soil can be explored for CO(2)- and microbe-assisted phytoextraction technology. Copyright © 2011 Elsevier B.V. All rights reserved.

Forcing Cesium into Higher Oxidation States Using Useful hard x-ray Induced Chemistry under High Pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sneed, D.; Pravica, M.; Kim, E.

This paper discusses our attempt to synthesize higher oxidation forms of cesium fluoride by pressurizing cesium fluoride in a fluorine-rich environment created via the x-ray decomposition of potassium tetrafluoroborate. This was done in order to confirm recent theoretical predictions of higher oxidation forms of CsFn. We discuss the development of a technique to produce molecular fluorine in situ via useful hard x-ray photochemistry, and the attempt to utilize this technique to form higher oxidation states of cesium fluoride. In order to verify the formation of the novel stoichiometric species of CsFn. X-ray Absorption Near Edge Spectroscopy (XANES) centered on themore » cesium K-edge was performed to probe the oxidation state of cesium as well as the local molecular coordination around Cs.« less

Optical cascade pumping of the 7P{sub 3/2} level in cesium atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kargapol'tsev, Sergei V; Velichansky, Vladimir L; Yarovitsky, Alexander V

2005-07-31

Doppler-free absorption spectra of resonance laser fields are studied upon two-stage excitation of cesium atoms according to the schemes 6S{sub 1/2{yields}}6P{sub 3/2{yields}}6D{sub 5/2} and 6S{sub 1/2{yields}}6P{sub 3/2{yields}}8S{sub 1/2}. The obtained experimental results are in qualitative agreement with the theory. In the case of weak absorption saturation, the width of resonances is mainly determined by two-photon transitions. The efficiencies of the two variants of two-stage excitation of the 7P{sub 3/2} level are compared. The possibility of fabrication of a gas laser operating on the 455-nm 7P{sub 3/2{yields}}6S{sub 1/2} transition with the optical depopulation of the lower operating level by an additionalmore » laser is discussed. (active media)« less

Simulation of cesium injection and distribution in rf-driven ion sources for negative hydrogen ion generation.

PubMed

Gutser, R; Fantz, U; Wünderlich, D

2010-02-01

Cesium seeded sources for surface generated negative hydrogen ions are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER. Stability and delivered current density depend highly on the cesium conditions during plasma-on and plasma-off phases of the ion source. The Monte Carlo code CSFLOW3D was used to study the transport of neutral and ionic cesium in both phases. Homogeneous and intense flows were obtained from two cesium sources in the expansion region of the ion source and from a dispenser array, which is located 10 cm in front of the converter surface.

Investigations of negative and positive cesium ion species

NASA Technical Reports Server (NTRS)

Chanin, L. M.

1978-01-01

A direct test is provided of the hypothesis of negative ion creation at the anode or collector of a diode operating under conditions simulating a cesium thermionic converter. The experimental technique involves using direct ion sampling through the collector electrode with mass analysis using a quadrupole mass analyzer. Similar measurements are undertaken on positive ions extracted through the emitter electrode. Measurements were made on a variety of gases including pure cesium, helium-cesium mixtures and cesium-hydrogen as well as cesium-xenon mixtures. The gas additive was used primarily to aid in understanding the negative ion formation processes. Measurements were conducted using emitter (cathode) temperatures up to about 1000 F. The major negative ion identified through the collector was Cs(-) with minor negative ion peaks tentatively identified as H(-), H2(-), H3(-), He(-) and a mass 66. Positive ions detected were believed to be Cs(+), Cs2(+) and Cs3(+).

Electro-kinetic remediation coupled with phytoremediation to remove lead, arsenic and cesium from contaminated paddy soil

PubMed Central

Mao, Xinyu; Han, Fengxiang X.; Shao, Xiaohou; Guo, Kai; McComb, Jacqueline; Arslan, Zikri; Zhang, Zhanyu

2017-01-01

The objectives of this study were to investigate distribution and solubility of Pb, Cs and As in soils under electrokinetic field and examine the processes of coupled electrokinetic phytoremediation of polluted soils. The elevated bioavailability and bioaccumulation of Pb, As and Cs in paddy soil under an electrokinetic field (EKF) were studied. The results show that the EKF treatment is effective on lowering soil pH to around 1.5 near the anode which is beneficial for the dissolution of metal(loid)s, thus increasing their overall solubility. The acidification in the anode soil efficiently increased the water soluble (SOL) and exchangeable (EXC) Pb, As and Cs, implying enhanced solubility and elevated overall potential bioavailability in the anode region while lower solubility in the cathode areas. Bioaccumulations of Pb, As and Cs were largely determined by the nature of elements, loading levels and EKF treatment. The native Pb in soil usually is not bioavailable. However, EKF treatment tends to transfer Pb to the SOL and EXC fractions improving the phytoextraction efficiency. Similarly, EKF transferred more EXC As and Cs to the SOL fraction significantly increasing their bioaccumulation in plant roots and shoots. Pb and As were accumulated more in plant roots than in shoots while Cs was accumulated more in shoots due to its similarity of chemical properties to potassium. Indian mustard, spinach and cabbage are good accumulators for Cs. Translocation of Pb, As and Cs from plant roots to shoots were enhanced by EKF. However, this study indicated the overall low phytoextraction efficiency of these plants. PMID:26650421

Evaluation of physicochemical properties of radioactive cesium in municipal solid waste incineration fly ash by particle size classification and leaching tests.

PubMed

Fujii, Kengo; Ochi, Kotaro; Ohbuchi, Atsushi; Koike, Yuya

2018-07-01

After the Fukushima Daiichi-Nuclear Power Plant accident, environmental recovery was a major issue because a considerable amount of municipal solid waste incineration (MSWI) fly ash was highly contaminated with radioactive cesium. To the best of our knowledge, only a few studies have evaluated the detailed physicochemical properties of radioactive cesium in MSWI fly ash to propose an effective method for the solidification and reuse of MSWI fly ash. In this study, MSWI fly ash was sampled in Fukushima Prefecture. The physicochemical properties of radioactive cesium in MSWI fly ash were evaluated by particle size classification (less than 25, 25-45, 45-100, 100-300, 300-500, and greater than 500 μm) and the Japanese leaching test No. 13 called "JLT-13". These results obtained from the classification of fly ash indicated that the activity concentration of radioactive cesium and the content of the coexisting matter (i.e., chloride and potassium) temporarily change in response to the particle size of fly ash. X-ray diffraction results indicated that water-soluble radioactive cesium exists as CsCl because of the cooling process and that insoluble cesium is bound to the inner sphere of amorphous matter. These results indicated that the distribution of radioactive cesium depends on the characteristics of MSWI fly ash. Copyright © 2018 Elsevier Ltd. All rights reserved.

Calix[4]pyrrole: A New Ion-Pair Receptor As Demonstrated by Liquid-Liquid Extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wintergerst, Mr. Matthieu; Levitskaia, Tatiana G.; Moyer, Bruce A

Solvent-extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and cesium bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to nitrobenzene was determined from plots of the cesium distribution ratios vs cesium salt and receptor concentration, indicating the formation of an ionpaired 1:1:1 cesium:calix[4]pyrrole:halide complex. The extraction results were modeled to evaluate the equilibria inherent to the solvent-extraction system, with either chloride or bromide. The binding energy between the halide anion and the calix[4]pyrrole was found to be about 7 kJ/mol larger for cesium chloride than for themore » cesium bromide. The ion-pairing free energies between the calix[4]pyrrole-halide complex and the cesium cation are nearly the same within experimental uncertainty for either halide, consistent with a structural model in which the Cs+ cation resides in the calix bowl. These results are unexpected since nitrobenzene is a polar solvent that generally leads to dissociated complexes in the organic phase when used as a diluent in extraction studies of univalent ions. Control studies involving nitrate revealed no evidence of ion pairing for CsNO3 under conditions identical to those where it is observed for CsCl and CsBr.« less

Calix[4]pyrrole: A New Ion-Pair Receptor As Demonstrated by Liquid-Liquid Extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wintergerst, Mr. Matthieu; Levitskaia, Tatiana G.; Moyer, Bruce A

Solvent extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and cesium bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to nitrobenzene was determined from plots of the cesium distribution ratios vs. cesium salt and receptor concentration, indicating the formation of an ion-paired 1:1:1 cesium:calix[4]pyrrole:halide complex. The extraction results were modeled to evaluate the equilibria inherent to the solvent extraction system, either with chloride or bromide. The binding energy between the halide anion and the calix[4]pyrrole was found to be about 7 kJ/mol larger for cesium chloride thanmore » for the cesium bromide. The ion-pairing free energies between the calix[4]pyrrole-halide complex and the cesium cation are nearly the same within experimental uncertainty for either halide, consistent with a structural model in which the Cs+ cation resides in the calix bowl. These results are unexpected since nitrobenzene is a very polar solvent that generally leads to dissociated complexes in the organic phase when used as a diluent in extraction studies of univalent ions. Control studies involving nitrate revealed no evidence of ion-pairing for CsNO3 under conditions identical to those where it is observed for CsCl and CsBr.« less

Fukushima- Ocean Impacts and Public Concerns

NASA Astrophysics Data System (ADS)

Buesseler, K.

2015-12-01

The triple disaster of the March 11, 2011 earthquake, tsunami, and subsequent radiation releases at Fukushima Dai-ichi were unprecedented events for the ocean and society. This presentation will provide an overview of studies of Fukushima radionuclides in the ocean. The radioactive releases from Fukushima will be compared to natural and prior human sources. The fate of cesium is largely determined by its soluble nature in seawater, though uptake in sediments does occur via cesium's association with both detrital particles and biological uptake and sedimentation. Cesium's continued supply from the rivers and ongoing leakages at the nuclear power plants suggests that coastal sediments may remain contaminated for decades to come. Although levels of cesium in the ocean and being released from Fukushima more than four years later are orders of magnitude lower than in 2011, other isotopes such as strontium-90 remain of interest as they are elevated relative to cesium in the groundwater and storage tanks at the reactor site. Across the Pacific, Fukushima cesium is starting to be detectable along the west coast of North America. Although models suggest cesium will be at levels well below those considered of human health concern, the public is worried about the lack of ocean monitoring of Fukushima radionuclides. We addressed these public concerns by creating "Our Radioactive Ocean" a citizen-scientist crowd-funded campaign that provides a sampling kit that can use to sample their favorite beach. Once collected, samples are returned to WHOI for analyses of the isotopes of cesium that allow us to distinguish Fukushima cesium from other sources (http://OurRadioactiveOcean.org ). However to measure the low levels of cesium already in the ocean 20 liter samples are needed. To increase public participation, we will also present results from a new wearable sample collector, the "RadBand" which contains a small amount of cesium selective resin that surfers and swimmers can wear on their ankle. A prototype RadBand is being tested as part of The Longest Swim, an attempt by Ben Lecomte to swim from Tokyo to San Francisco (http://thelongestswim.com/ ). This swim is being used as another way to engage the public on ocean and environmental issues.

Behavior of radionuclides in sanitary landfills.

PubMed

Chang, K C; Chian, E S; Pohland, F G; Cross, W H; Roland, L; Kahn, B

1984-01-01

his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, S.; Wong, C.F.; Buckley, L.P.

1994-11-22

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, Sivaraman; Wong, Chi F.; Buckley, Leo P.

1994-01-01

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Development of a water purifier for radioactive cesium removal from contaminated natural water by radiation-induced graft polymerization

NASA Astrophysics Data System (ADS)

Seko, Noriaki; Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya; Saiki, Seiichi; Ueki, Yuji

2018-02-01

Six years after the Fukushima-nuclear accident, the dissolved radioactive cesium (Cs) is now hardly detected in environmental natural waters. These natural waters are directly used as source of drinking and domestic waters in disaster-stricken areas in Fukushima. However, the possibility that some radioactive Cs adsorbed on soil or leaves will contaminate these natural waters during heavy rains or typhoon is always present. In order for the returning residents to live with peace of mind, it is important to demonstrate the safety of the domestic waters that they will use for their daily life. For this purpose, we have synthesized a material for selective removal of radioactive Cs by introducing ammonium 12-molybdophosphate (AMP) onto polyethylene nonwoven fabric through radiation-induced emulsion graft polymerization technique. Water purifiers filled with the grafted Cs adsorbent were installed in selected houses in Fukushima. The capability of the grafted adsorbent to remove Cs from domestic waters was evaluated for a whole year. The results showed that the tap water filtered through the developed water purifier contained no radioactive Cs, signifying the very effective adsorption performance of the developed grafted adsorbent. From several demonstrations, we have commercialized the water purifier named "KranCsair®". Furthermore, we have also developed a method for the mass production of the grafted nonwoven fabric. Using a 30 L grafting reactor, it was possible to produce the grafted nonwoven fabric with a suitable range of degree of grafting. When an irradiated roll of nonwoven trunk fabric with a length of 10 m and a width of 30 cm was set in the reactor filled with glycidyl methacrylate (GMA), AMP, Tween 80 monomer emulsion solution at 40 °C for 1 h, the difference of Dgs in the length and the width on roll of fabrics was negligible.

Distribution of radioactive cesium ((134)Cs Plus(137)Cs) in a contaminated Japanese soybean cultivar during the preparation of tofu, natto, and nimame (Boiled Soybean).

PubMed

Hachinohe, Mayumi; Kimura, Keitarou; Kubo, Yuji; Tanji, Katsuo; Hamamatsu, Shioka; Hagiwara, Shoji; Nei, Daisuke; Kameya, Hiromi; Nakagawa, Rikio; Matsukura, Ushio; Todoriki, Setsuko; Kawamoto, Shinichi

2013-06-01

We investigated the fate of radioactive cesium ((134)Cs plus (137)Cs) during the production of tofu, natto, and nimame (boiled soybean) from a contaminated Japanese soybean cultivar harvested in FY2011. Tofu, natto, and nimame were made from soybean grains containing radioactive cesium (240 to 340 Bq/kg [dry weight]), and the radioactive cesium in the processed soybean foods and in by-product fractions such as okara, broth, and waste water was measured with a germanium semiconductor detector. The processing factor is the ratio of radioactive cesium concentration of a product before and after processing. For tofu, natto, nimame, and for the by-product okara, processing factors were 0.12, 0.40, 0.20, and 0.18, respectively; this suggested that these three soybean foods and okara, used mainly as an animal feed, can be considered safe for human and animal consumption according to the standard limit for radioactive cesium of soybean grains. Furthermore, the ratio of radioactive cesium concentrations in the cotyledon, hypocotyl, and seed coat portions of the soybean grain was found to be approximately 1:1:0.4.

Negative ion production in large volume source with small deposition of cesium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacquot, C.; Pamela, J.; Riz, D.

1996-03-01

Experimental data on the enhancement of D{sup {minus}} (H{sup {minus}}) negative ion production due to cesium injection into a large volume multiampere negative ion source (MANTIS) are described. The directed deposition of small cesium amounts (5{endash}100 mg) from a compact, movable oven, placed into the central part of a MANTIS gas-discharge box was used. A calorimetrically measured D{sup {minus}} beam with an intensity up to 1.6 A and an extracted current density up to 4.2 mA/cm{sup 2} (beam energy 25 kV) was obtained. Exactly 30 mg of cesium provides at least one month of source operation (1000 pulses with amore » discharge pulse duration of 4 s). The effect of cesium on NI enhancement was immediately displayed after the distributed Cs deposition, but it needed some {open_quote}{open_quote}conditioning{close_quote}{close_quote} of cesium by tens of discharge pulses (or by several hours {open_quote}{open_quote}pause{close_quote}{close_quote}) in the case of a localized Cs deposition. No degradation of extraction-acceleration voltage holding on within the tested range of cesium injection was observed. {copyright} {ital 1996 American Institute of Physics.}« less

High voltage holding in the negative ion sources with cesium deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belchenko, Yu.; Abdrashitov, G.; Ivanov, A.

High voltage holding of the large surface-plasma negative ion source with cesium deposition was studied. It was found that heating of ion-optical system electrodes to temperature >100 °C facilitates the source conditioning by high voltage pulses in vacuum and by beam shots. The procedure of electrode conditioning and the data on high-voltage holding in the negative ion source with small cesium seed are described. The mechanism of high voltage holding improvement by depletion of cesium coverage is discussed.

Metal cluster's effect on the optical properties of cesium bromide thin films

NASA Astrophysics Data System (ADS)

Kumar, Kuldeep; Arun, P.; Ravi Kant, Chhaya; Juluri, Bala Krishna

2012-06-01

Cesium bromide (CsBr) films grown on glass substrates by thermal evaporation showed prominent absorption peaks in the UV-visible region. Interestingly, these absorption spectra showed peaks which red shifted over time in ambient exposure. Structural and morphological studies suggested decrease in particle size overtime which was unusual. Electron micrographs show the formation of "daughter" cesium nanorods from parent CsBr particles. Theoretical calculations show the optical behavior observed to be due to localized surface plasmon resonance resulting from cesium nanorods.

[Reduction of radioactive cesium content in pond smelt by cooking].

PubMed

Nabeshi, Hiromi; Tsutsumi, Tomoaki; Hachisuka, Akiko; Matsuda, Rieko

2013-01-01

In Japan, seafood may be eaten raw or after having been cooked in diverse ways. Therefore, it is important to understand the effect of cooking on the extent of contamination with radioactive materials in order to avoid internal exposure to radioactive materials via seafood. In this study, we investigated the changes in radioactive cesium content in pond smelt cooked in four different ways: grilled, stewed (kanroni), fried and soaked (nanbanzuke). The radioactive cesium content in grilled, kanroni and fried pond smelt was almost unchanged compared with the uncooked state. In contrast, radioactive cesium content in nanbanzuke pond smelt was decreased by about 30%. Our result suggests that soaking cooked pond smelt in seasoning is an effective method of reducing the burden radioactive cesium.

Low-energy vibrational dynamics of cesium borate glasses.

PubMed

Crupi, C; D'Angelo, G; Vasi, C

2012-06-07

Low-temperature specific heat and inelastic light scattering experiments have been performed on a series of cesium borate glasses and on a cesium borate crystal. Raman measurements on the crystalline sample have revealed the existence of cesium rattling modes in the same frequency region where glasses exhibit the boson peak (BP). These localized modes are supposed to overlap with the BP in cesium borate glasses affecting its magnitude. Their influence on the low frequency vibrational dynamics in glassy samples has been considered, and their contribution to the specific heat has been estimated. Evidence for a relation between the changes of the BP induced by the increased amount of metallic oxide and the variations of the elastic medium has been provided.

Effect of the cesium and potassium doping of multiwalled carbon nanotubes grown in an electrical arc on their emission characteristics

NASA Astrophysics Data System (ADS)

Izrael'yants, K. R.; Orlov, A. P.; Ormont, A. B.; Chirkova, E. G.

2017-04-01

The effect of cesium and potassium atoms deposited onto multiwalled carbon nanotubes grown in an electrical arc on their emission characteristics was studied. The current-voltage characteristics of the field electron emission of specimens with cesium or potassium doped multiwalled carbon nanotubes of this type were revealed to retain their linear character in the Fowler-Nordheim coordinates within several orders of magnitude of change in the emission current. The deposition of cesium and potassium atoms was shown to lead to a considerable increase in the emission current and a decrease in the work function φ of studied emitters with multiwalled nanotubes. The work function was established to decrease to φ 3.1 eV at an optimal thickness of coating with cesium atoms and to φ 2.9 eV in the case of doping with potassium atoms. Cesium and potassium deposition conditions optimal for the attainment of a maximum emission current were found.

Adsorption of cesium on cement mortar from aqueous solutions.

PubMed

Volchek, Konstantin; Miah, Muhammed Yusuf; Kuang, Wenxing; DeMaleki, Zack; Tezel, F Handan

2011-10-30

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(-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 (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(-1) while the respective surface concentration on coupons varied from 0.0395 to 22.34 μg cm(-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(-1) suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Environmental remediation following the Fukushima-Daiichi accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tagawa, A.; Miyahara, K.; Nakayama, S.

2013-07-01

A wide area of Fukushima Prefecture was contaminated with radioactivity released by the Fukushima Daiichi nuclear accident. The decontamination pilot projects conducted by JAEA aimed at demonstrating the applicability of different techniques to rehabilitate affected areas. As most radioactive cesium is concentrated at the top of the soil column and strongly bound to mineral surfaces, there are 3 options left to decrease the gamma dose rate (usually measured 1 m above the ground surface): the stripping of the contaminated topsoil (i.e. direct removal of cesium), the dilution by mixing and the soil profile inversion. The last two options do notmore » generate waste. As the half-distance of {sup 137}Cs gammas in soil is in the order of 5-6 cm (depending on density and water content), the shielding by 50 cm of uncontaminated deep soil would theoretically reduce gamma doses by about 3 orders of magnitude. Which option is employed depends basically on the Cesium concentration in the topsoil, averaged over a 15-cm thickness. The JAEA's decontamination pilot projects focus on soil profile inversion and topsoil stripping. Two different techniques have been tested for the soil profile inversion: one is the reversal tillage by which surface soil of thickness of several tens of cm is reversed by using a tractor plough and the other is the complete interchanging of contaminated topsoil with uncontaminated subsoil by using a back-hoe. Reversal tillage with a tractor plough cost about 30 yen/m{sup 2}, which is an order of magnitude lower than that of topsoil-subsoil interchange (about 300 yen/m{sup 2}). Topsoil stripping is significantly more costly (between 550 yen/m{sup 2} and 690 yen/m{sup 2} according to the equipment used)« less

Analysis of Breakthrough Profiles Based on Gamma Ray Emission Along Loaded Packed Bed Columns: Comparative Evaluation of Ionsiv IE-911 and Chabazite Zeolite for the Removal of Radiostrontium and Cesium from Groundwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bostick, D.T.; DePaoli, S.M.; Lucero, A.J.

1999-10-18

A gamma counting system has been assembled that can profile the breakthrough fronts of gamma-emitting radioisotopes longitudinally and axially along a loaded column. This profiling technique has been particularly useful in columns studies such as those performed with IONSP IE-911, a crystalline silicotitanate (CST) manufactured by UOP, in which unusually long operating times are required to observe cesium breakthrough in column effluent. The length of the mass transfer zone and extent of column saturation can be detected early in a column study by viewing the relative emission of gamma emitters along I the length of the column. In this study,more » gamma scans were used to analyze loaded CST and zeolite columns used in the treatment of process wastewater simulant and actual groundwater. Results indicate good run-to-run reproductibility in acquiring the scans. The longitudinal gamma scans for both {sup 90}Sr and {sup 137}Cs conformed with breakthrough results reported on the basis of column effluent activity. Although not obvious from data obtained by monitoring effluent activity, the gamma scans indicated that both cesium and strontium in the saturated zone of the CST column are slowly displaced by the higher levels of groundwater cations and are then resorbed further down the column. This displacement phenomenon identified by gamma scans was verified using data from a zeolite column, in which both the gamma scan and column effluent data exhibited radionuclide displacement by groundwater cations. The gamma emission intensities from the CST column runs are used to quantitate and compare the distribution coefficient and loading capacity of {sup 137}Cs on CST versus zeolite.« less

Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Tara E.; Scherman, Carl; Martin, David

Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilitiesmore » and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.« less

Some services of the Time and Frequency Division of the National Bureau of Standards

NASA Technical Reports Server (NTRS)

Barnes, J. A.

1973-01-01

The Time and Frequency Division of the National Bureau of Standards (NBS) provides several services to the general public. The radio broadcasts of WWV, WWVH, and WWVB supply reliable, unambiguous time signals to many users. The NBS telephone time-of-day service attracts several hundreds of thousands of calls each year. Periodically, the NBS provides courses on specific topics relating to time and frequency technology. In addition to numerous technical papers published each year, the NBS has prepared the first volume of a comprehensive monograph on time and frequency. The results of research in the Time and Frequency Division of the NBS have had significant impact. An active TV time system capable of serving most of the U.S. currently awaits a ruling by the FCC on a petition filed last year on behalf of the NBS by the Department of Commerce. Three more recent developments are: (1) a TV frequency comparator (patent applied for); (2) a method to perform an independent (absolute) frequency evaluation of commercial cesium beam oscillators; and (3) a method of removing one source of frequency drift in commercial cesium beam oscillators.

Tank 19F Folding Crawler Final Evaluation, Rev. 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nance, T.

2000-10-25

The Department of Energy (DOE) is committed to removing millions of gallons of high-level radioactive waste from 51 underground waste storage tanks at the Savannah River Site (SRS). The primary radioactive waste constituents are strontium, plutonium,and cesium. It is recognized that the continued storage of this waste is a risk to the public, workers, and the environment. SRS was the first site in the DOE complex to have emptied and operationally closed a high-level radioactive waste tank. The task of emptying and closing the rest of the tanks will be completed by FY28.

Radiological Conditions on Rongelap Atoll: Perspective on Resettlement of Rongelap Atoll

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, T F

2003-02-01

The most widely accepted international guidelines for protection of the public from ionizing radiation and in circumstances related to intervention strategies to reduce exposures to preexisting conditions, such as those on Rongelap Island, come from the International Commission on Radiological Protection, the National Council on Radiation Protection and the International Atomic Energy Agency. By all internationally agreed scientific criteria, present radiological conditions on Rongelap Island are considered safe for permanent resettlement. Safe implies that no additional cancer deaths are expected among those living on Rongelap Island beyond the number that would occur in a community of the same population size,more » similar ages and mix of males and females, who do not experience exposure to residual fallout by living on the island. It is expected that the average dose received by Rongelap Island residents will fall well below the dose adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal considered a ''safe'' or acceptable health risk. These conclusions are supported by environmental measurements and assessments performed by the Lawrence Livermore National Laboratory (LLNL) including the results of radiological surveillance of resettlement workers living on Rongelap Island for various lengths of time from 1999 through 2002, and independent studies conducted by Japanese scientists. Atmospheric testing of nuclear weapons was responsible for the widespread dispersion of radioactive fallout around the globe. Rongelap Island received higher levels of fallout from local or close-in fallout deposition from nuclear testing on Bikini Atoll. The main pathway for exposure to radiation from the bomb testing is ''internally'' through ingestion of radioactive cesium (cesium-137) taken up from the soil into locally grown foodstuffs. Resettlement workers living on Rongelap Island who ate local foods have volunteered to have the cesium-137 content of their bodies measured. The measuring device is called a whole body counter. A person relaxes in a chair for a few minutes while counts are taken using a detector a few inches away from the body. The whole body counting program on Rongelap Island was established under a cooperative agreement between the Rongelap Atoll Local Government (RALG), the Republic of the Marshall Islands and the U.S. Department of Energy (DOE). Local technicians from Rongelap continue to operate the facility under supervision of scientists from LLNL. Whole body counting data collected on resettlement workers during the initial phases of resettlement can tell us what exposure level a permanently resettled population could reasonably expect. The average internal dose to resettlement workers from cesium-137 is less than 1 mrem (0.01 mSv) per year. The highest individual dose observed over the last 3-years was less than 4 mrem (0.04 mSv) per year. The RALG-DOE resettlement support plan also calls for spreading potassium fertilizer across the agricultural areas to prevent the uptake of cesium-137 into plants. Fertilization will reduce the dietary intake of cesium-137 and reduce the dose to island residents. By 2004, over 70 percent of the cesium-137 deposition in soil from fallout in 1954 will have decayed to a non-radioactive substance. Over the next 10-20 years, more than one-half of the remaining cesium-137 in the soil and vegetation of the atoll islands will have disappeared by decay or washed out of the soil by rain. Removing some soil, applying crushed coral around living areas, and spreading potassium fertilizer across agricultural areas will reduce the level of radiation exposure in the resettled population to levels below those considered safe by the Nuclear Claims Tribunal and to levels well below those considered safe by the international scientific community.« less

Absorption of Radionuclides from the Fukushima Nuclear Accident by a Novel Algal Strain

PubMed Central

Shimura, Hiroki; Itoh, Katsuhiko; Sugiyama, Atsushi; Ichijo, Sayaka; Ichijo, Masashi; Furuya, Fumihiko; Nakamura, Yuji; Kitahara, Ken; Kobayashi, Kazuhiko; Yukawa, Yasuhiro; Kobayashi, Tetsuro

2012-01-01

Large quantities of radionuclides have leaked from the Fukushima Daiichi Nuclear Power Plant into the surrounding environment. Effective prevention of health hazards resulting from radiation exposure will require the development of efficient and economical methods for decontaminating radioactive wastewater and aquatic ecosystems. Here we describe the accumulation of water-soluble radionuclides released by nuclear reactors by a novel strain of alga. The newly discovered green microalgae, Parachlorella sp. binos (Binos) has a thick alginate-containing extracellular matrix and abundant chloroplasts. When this strain was cultured with radioiodine, a light-dependent uptake of radioiodine was observed. In dark conditions, radioiodine uptake was induced by addition of hydrogen superoxide. High-resolution secondary ion mass spectrometry (SIMS) showed a localization of accumulated iodine in the cytosol. This alga also exhibited highly efficient incorporation of the radioactive isotopes strontium and cesium in a light-independent manner. SIMS analysis showed that strontium was distributed in the extracellular matrix of Binos. Finally we also showed the ability of this strain to accumulate radioactive nuclides from water and soil samples collected from a heavily contaminated area in Fukushima. Our results demonstrate that Binos could be applied to the decontamination of iodine, strontium and cesium radioisotopes, which are most commonly encountered after nuclear reactor accidents. PMID:22984475

CW 3μm lasing via two-photon pumping in cesium vapor with a 1W source

NASA Astrophysics Data System (ADS)

Haluska, Nathan D.; Rice, Christopher A.; Perram, Glen P.

2018-02-01

We report the first CW lasing from two-photon pumping via a virtual state. Pulsed and the CW lasing of the 3096 nm 72 P1/2 to 72 S1/2 line are observed from degenerate two-photon pumping of the cesium 72 S1/2 to 62 D3/2 transition. High intensity pulses excite over 17 lasing wavelengths. Under lower intensity CW excitation, 3 μm lasing is still observed with efficiencies of 0.7%. CW experiments utilized a Cs heat pipe at 150 °C to 270 °C, and a highly-focused, single pass, Ti-Sapphire pump with no aid of a cavity. Unlike normal DPALS, this architecture does not require buffer gas, and heat is released optically so a flowing system is not required. Both suggest a very simple device with excellent beam quality is possible. This proof of concept can be greatly enhanced with more optimal conditions such as non-degenerate pumping to further increase the two-photon pump cross section and the addition of a cavity to improve mode volume overlap. These improvements may lead to an increase in efficiencies to a theoretical maximum of 14%. Results suggest two-photon pumping with diodes is feasible.

Distillation device supplies cesium vapor at constant pressure

NASA Technical Reports Server (NTRS)

Basiulis, A.; Shefsiek, P. K.

1968-01-01

Distillation apparatus in the form of a U tube supplies small amounts of pure cesium vapor at constant pressure to a thermionic converter. The upstream leg of the U tube is connected to a vacuum pump to withdraw noncondensable impurities, the bottom portion serves as a reservoir for the liquid cesium.

Recovery of cesium and palladium from nuclear reactor fuel processing waste

DOEpatents

Campbell, David O.

1976-01-01

A method of recovering cesium and palladium values from nuclear reactor fission product waste solution involves contacting the solution with a source of chloride ions and oxidizing palladium ions present in the solution to precipitate cesium and palladium as Cs.sub.2 PdCl.sub.6.

Historical Cost Curves for Hydrogen Masers and Cesium Beam Frequency and Timing Standards

NASA Technical Reports Server (NTRS)

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.

An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birdwell Jr, Joseph F; Lee, Denise L; Taylor, Paul Allen

2010-09-01

A small column ion exchange (SCIX) system has been proposed for removal of cesium from caustic, supernatant, and dissolved salt solutions stored or generated from high-level tank wastes at the US Department of Energy (DOE) Hanford Site and Savannah River Sites. In both instances, deployment of SCIX systems, either in-tank or near-tank, is a means of expediting waste pretreatment and dispositioning with minimal or no new infrastructure requirements. Conceptually, the treatment approach can utilize a range of ion exchange media. Previously, both crystalline silicotitanate (CST), an inorganic, nonelutable sorbent, and resorcinol-formaldehyde (RF), an organic, elutable resin, have been considered formore » cesium removal from tank waste. More recently, Pacific Northwest National Laboratory (PNNL) evaluated use of SuperLig{reg_sign} 644, an elutable ion exchange medium, for the subject application. Results of testing indicate hydraulic limitations of the SuperLig{reg_sign} resin, specifically a high pressure drop through packed ion exchange columns. This limitation is likely the result of swelling and shrinkage of the irregularly shaped (granular) resin during repeated conversions between sodium and hydrogen forms as the resin is first loaded then eluted. It is anticipated that a similar flow limitation would exist in columns packed with conventional, granular RF resin. However, use of spherical RF resin is a likely means of mitigating processing limitations due to excessive pressure drop. Although size changes occur as the spherical resin is cycled through loading and elution operations, the geometry of the resin is expected to effectively mitigate the close packing that leads to high pressure drops across ion exchange columns. Multiple evaluations have been performed to determine the feasibility of using spherical RF resin and to obtain data necessary for design of an SCIX process. The work performed consisted of examination of radiation effects on resin performance, quantification of cesium adsorption performance as a function of operating temperature and pH, and evaluation of sodium uptake (titration) as function of pH and counteranion concentration. The results of these efforts are presented in this report. Hydraulic performance of the resin and the use of eluant alternatives to nitric acid have also been evaluated and have been reported elsewhere (Taylor 2009, Taylor and Johnson 2009).« less

Reviews of a Diode-Pumped Alkali Laser (DPAL): a potential high powered light source

NASA Astrophysics Data System (ADS)

Cai, He; Wang, You; Han, Juhong; An, Guofei; Zhang, Wei; Xue, Liangping; Wang, Hongyuan; Zhou, Jie; Gao, Ming; Jiang, Zhigang

2015-03-01

Diode pumped alkali vapor lasers (DPALs) were first developed by in W. F. Krupke at the beginning of the 21th century. In the recent years, DPALs have been rapidly developed because of their high Stokes efficiency, good beam quality, compact size and near-infrared emission wavelengths. The Stokes efficiency of a DPAL can achieve a miraculous level as high as 95.3% for cesium (Cs), 98.1% for rubidium (Rb), and 99.6% for potassium (K), respectively. The thermal effect of a DPAL is theoretically smaller than that of a normal diode-pumped solid-state laser (DPSSL). Additionally, generated heat of a DPAL can be removed by circulating the gases inside a sealed system. Therefore, the thermal management would be relatively simple for realization of a high-powered DPAL. In the meantime, DPALs combine the advantages of both DPSSLs and normal gas lasers but evade the disadvantages of them. Generally, the collisionally broadened cross sections of both the D1 and the D2 lines for a DPAL are much larger than those for the most conventional solid-state, fiber and gas lasers. Thus, DPALs provide an outstanding potentiality for realization of high-powered laser systems. It has been shown that a DPAL is now becoming one of the most promising candidates for simultaneously achieving good beam quality and high output power. With a lot of marvelous merits, a DPAL becomes one of the most hopeful high-powered laser sources of next generation.

The role of silica colloids on facilitated cesium transport through glass bead columns and modeling

NASA Astrophysics Data System (ADS)

Noell, Alan L.; Thompson, Joseph L.; Corapcioglu, M. Yavuz; Triay, Inés R.

1998-05-01

Groundwater colloids can act as a vector which enhances the migration of contaminants. While sorbed to mobile colloids, contaminants can be held in the aqueous phase which prevents them from interacting with immobile aquifer surfaces. In this study, an idealized laboratory set-up was used to examine the influence of amorphous silica colloids on the transport of cesium. Synthetic groundwater and saturated glass bead columns were used to minimize the presence of natural colloidal material. The columns were assembled in replicate, some packed with 150-210 μm glass bead and others packed with 355-420 μm glass beads. The colloids used in these experiments were 100 nm amorphous silica colloids from Nissan Chemical Company. In the absence of these colloids, the retardation factor for cesium was 8.0 in the 150-210 μm glass bead columns and 3.6 in the 355-420 μm glass bead columns. The influence of anthropogenic colloids was tested by injecting 0.09 pore volume slugs of an equilibrated suspension of cesium and colloids into the colloid-free columns. Although there was little noticeable facilitation in the smaller glass bead columns, there was a slight reduction in the retardation of cesium in the larger glass bead columns. This was attributed to cesium having less of a retention time in the larger glass bead columns. When cesium was injected into columns with a constant flux of colloids, the retardation of cesium was reduced by 14-32% in the 150-210 μm glass bead columns and by 38-51% in the 355-420 μm glass bead columns. A model based on Corapcioglu and Jiang (1993) [Corapcioglu, M.Y., Jiang, S., 1993. Colloid-facilitated groundwater contaminant transport, Water Resour. Res., 29 (7) 2215-2226] was compared with the experimental elution data. When equilibrium sorption expressions were used and the flux of colloids through the glass bead columns was constant, the colloid facilitated transport of cesium was able to be described using an effective retardation coefficient. Fully kinetic simulations, however, more accurately described the colloid facilitated transport of cesium.

A long-term stability study of Prussian blue: A quality assessment of water content and cesium binding.

PubMed

Mohammad, Adil; Yang, Yongsheng; Khan, Mansoor A; Faustino, Patrick J

2015-01-25

Prussian blue (PB) is the active pharmaceutical ingredient (API) of Radiogardase, the first approved medical countermeasure for the treatment of radiocesium poisoning in the event of a major radiological incident such as a "dirty bomb" or nuclear attack. The purpose of this study is to assess the long-term stability of Prussian blue drug products (DPs) and APIs under laboratory storage condition by monitoring the loss in water content and the in vitro cesium binding. The water content was measured by thermal gravimetric analysis (TGA). The in-vitro cesium binding study was conducted using a surrogate model to mimic gastric residence and intestinal transport. Free cesium was analyzed using a validated flame atomic emission spectroscopy (AES) method. The binding equilibrium was reached at 24h. The Langmuir isotherm was plotted to calculate the maximum binding capacity (MBC). Comparison of the same PB samples with 2003 data samples, the water content of both APIs and DPs decreased on an average by approximately 12-24%. Consequently, the MBC of cesium was decreased from 358mg/g in 2003 to 265mg/g @ pH 7.5, a decrease of approximately 26%. The binding of cesium is also pH dependent with lowest binding at pH 1.0 and maximum binding at pH 7.5. At pH 7.5, the amount of cesium bound decreased by an average value of 7.9% for APIs and 8.9% for DPs (for 600ppm initial cesium concentration). These findings of water loss, pH dependence and decrease in cesium binding are consistent with our previously published data in 2003. Over last 10 years the stored DPs and APIs of PB have lost about 20% of water which has a negative impact on the PB cesium binding, however PB still meets the FDA specification of >150mg/g at equilibrium. The study is the first quantitative assessment of the long-term stability of PB and directs that proper long-term and short-term storage of PB is required to ensure that it is safe and efficacious at the time of an emergency situation. Published by Elsevier B.V.

Special treatment reduces helium permeation of glass in vacuum systems

NASA Technical Reports Server (NTRS)

Bryant, P. J.; Gosselin, C. M.

1966-01-01

Internal surfaces of the glass component of a vacuum system are exposed to cesium in gaseous form to reduce helium permeation. The cesium gas is derived from decomposition of cesium nitrate through heating. Several minutes of exposure of the internal surfaces of the glass vessel are sufficient to complete the treatment.

Development of an optically-pumped cesium standard at the Aerospace Corporation

NASA Technical Reports Server (NTRS)

Chan, Yat C.

1992-01-01

We have initiated a research program to study the performance of compact optically-pumped cesium (Cs) frequency standards, which have potential for future timekeeping applications in space. A Cs beam clock apparatus has been assembled. Basic functions of the frequency standard have been demonstrated. Clock signals are observed with optical pumping schemes using one or two lasers. With two laser pumping, we are able to selectively place up to 80 percent of the atomic population into one of the clock transition states. The observed pattern of clock signal indicates that the velocity distribution of the Cs atoms contributing to the microwave signal is beam-Maxwellian. Thus, in the optically-pumped Cs frequency standards, the entire Cs population in the atomic beam could be utilized to generate the clock signals. This is in contrast to the conventional Cs beam standards where only approx. 1 percent of the atoms in the beam are used. More efficient Cs consumption can lead to improved reliability and increased useful lifetime of the clock.

The effect of mineral composition on the sorption of cesium ions on geological formations.

PubMed

Kónya, József; Nagy, Noémi M; Nemes, Zoltán

2005-10-15

The sorption of cesium-137 on rock samples, mainly on clay rocks, is determined as a function of the mineral composition of the rocks. A relation between the mineral groups (tectosilicates, phyllosilicates, clay minerals, carbonates) and their cesium sorption properties is shown. A linear model is constructed by which the distribution coefficients of the different minerals can be calculated from the mineral composition and the net distribution coefficient of the rock. On the basis of the distribution coefficients of the minerals the cesium sorption properties of other rocks can be predicted.

Carbonation-induced weathering effect on cesium retention of cement paste

NASA Astrophysics Data System (ADS)

Park, S. M.; Jang, J. G.

2018-07-01

Carbonation is inevitable for cement and concrete in repositories over an extended period of time. This study investigated the carbonation-induced weathering effect on cesium retention of cement. Cement paste samples were exposed to accelerated carbonation for different durations to simulate the extent of weathering among samples. The extent of carbonation in cement was characterized by XRD, TG and NMR spectroscopy, while the retention capacity for cesium was investigated by zeta potential measurement and batch adsorption tests. Though carbonation led to decalcification from the binder gel, it negatively charged the surface of cement hydrates and enhanced their cesium adsorption capacity.

ION ROCKET ENGINE

DOEpatents

Ehlers, K.W.; Voelker, F. III

1961-12-19

A thrust generating engine utilizing cesium vapor as the propellant fuel is designed. The cesium is vaporized by heat and is passed through a heated porous tungsten electrode whereby each cesium atom is fonized. Upon emergfng from the tungsten electrode, the ions are accelerated rearwardly from the rocket through an electric field between the tungsten electrode and an adjacent accelerating electrode grid structure. To avoid creating a large negative charge on the space craft as a result of the expulsion of the positive ions, a source of electrons is disposed adjacent the ion stream to neutralize the cesium atoms following acceleration thereof. (AEC)

Results of Several Years Experiments on the Absorption of Radioactive Strontium and Cesium by Cultivated Plants; COMPTE RENDU D'EXPERIENCES DE PLUSIEURS ANNEES SUR L'ABSORPTION DU STRONTIUM ET DU CESIUM RADIOACTIES PAR DES PLANTES CULTIVEES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huguet, F. et al.

1962-01-01

The absorption of cesium-137 and strontium-90 by vines, permanent pasture, potatoes, green vegetables, tomatoes, onions, cabbage, and beans in France in 1960 is presented. The strontium coefficient has varied very little from one year to the next and that of cesium has slightly diminished. The values obtained suggest that the concentrations in irrigation water should not exceed one fifth of the maximum permissible concentration in drinking water. (auth)

Restoration of water environment contaminated by radioactive cesium released from Fukushima Daiichi NPP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeshita, K.; Takahashi, H.; Jinbo, Y.

2013-07-01

In the Fukushima Daiichi NPP Accident, large amounts of volatile radioactive nuclides, such as {sup 131}I, {sup 134}Cs and {sup 137}Cs, were released to the atmosphere and huge areas surrounding the nuclear site were contaminated by the radioactive fallout. In this study, a combined process with a hydrothermal process and a coagulation settling process was proposed for the separation of radioactive Cs from contaminated soil and sewage sludge. The coagulation settling operation uses Prussian Blue (Ferric ferrocyanide) and an inorganic coagulant. The recovery of Cs from sewage sludge sampled at Fukushima city (100.000 Bq/kg) and soil at a nearby villagemore » (55.000 Bq/kg), was tested. About 96% of Cs in the sewage sludge was removed successfully by combining simple hydrothermal decomposition and coagulation settling. However, Cs in the soil was not removed sufficiently by the combined process (Cs removal is only 56%). The hydrothermal decomposition with blasting was carried out. The Cs removal from the soil was increased to 85%. When these operations were repeated twice, the Cs recovery was over 90%. The combined process with hydrothermal blasting and coagulation settling is applicable to the removal of Cs from highly contaminated soil.« less

Electro-kinetic remediation coupled with phytoremediation to remove lead, arsenic and cesium from contaminated paddy soil.

PubMed

Mao, Xinyu; Han, Fengxiang X; Shao, Xiaohou; Guo, Kai; McComb, Jacqueline; Arslan, Zikri; Zhang, Zhanyu

2016-03-01

The objectives of this study were to investigate distribution and solubility of Pb, Cs and As in soils under electrokinetic field and examine the processes of coupled electrokinetic phytoremediation of polluted soils. The elevated bioavailability and bioaccumulation of Pb, As and Cs in paddy soil under an electro-kinetic field (EKF) were studied. The results show that the EKF treatment is effective on lowering soil pH to around 1.5 near the anode which is beneficial for the dissolution of metal(loid)s, thus increasing their overall solubility. The acidification in the anode soil efficiently increased the water soluble (SOL) and exchangeable (EXC) Pb, As and Cs, implying enhanced solubility and elevated overall potential bioavailability in the anode region while lower solubility in the cathode areas. Bioaccumulations of Pb, As and Cs were largely determined by the nature of elements, loading levels and EKF treatment. The native Pb in soil usually is not bioavailable. However, EKF treatment tends to transfer Pb to the SOL and EXC fractions improving the phytoextraction efficiency. Similarly, EKF transferred more EXC As and Cs to the SOL fraction significantly increasing their bioaccumulation in plant roots and shoots. Pb and As were accumulated more in plant roots than in shoots while Cs was accumulated more in shoots due to its similarity of chemical properties to potassium. Indian mustard, spinach and cabbage are good accumulators for Cs. Translocation of Pb, As and Cs from plant roots to shoots were enhanced by EKF. However, this study indicated the overall low phytoextraction efficiency of these plants. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrogels Containing Prussian Blue Nanoparticles Toward Removal of Radioactive Cesium Ions.

PubMed

Kamachi, Yuichiro; Zakaria, Mohamed B; Torad, Nagy L; Nakato, Teruyuki; Ahamad, Tansir; Alshehri, Saad M; Malgras, Victor; Yamauchil, Yusuke

2016-04-01

Recent reports have demonstrated the practical application of Prussian blue (PB) nanoparticles toward environmental clean-up of radionuclide 173Cs. Herein, we prepared a large amount of PB nanoparticles by mixing both iron(III) chloride and sodium ferrocyanide hydrate as starting precursors. The obtained PB nanoparticles show a high surface area (440 m2. g-1) and consequently an excellent uptake ability of Cs ions from aqueous solutions. The uptake ability of Cs ions into poly(N-isopropylacrylamide (PNIPA) hydrogel is drastically increased up to 156.7 m2. g-1 after incorporating our PB nanoparticles, compared to 30.2 m2 . g-1 after using commercially available PB. Thus, our PB-containing PNIPA hydrogel can be considered as an excellent candidate for the removal of Cs ions from aqueous solutions, which will be useful for the remediation of the nuclear waste.

Effect of Sodium Hydroxide Pretreatment of UOP IONSIV IE-911 Crystalline Silicotitanate Sorbent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilmarth, W.R.

2000-08-29

Use of crystalline silicotitanate (CST) to remove cesium represents one of the alternatives identified for High Level Waste pretreatment at the Savannah River Site (SRS). Previous deployment of CST in the Department of Energy complex subjected the material to mildly caustic environments. Processing of SRS waste will expose CST to very alkaline solutions for extended period of time (typically 12 months in the proposed design). Results of elevated temperature stability tests showed that silicon and one of the proprietary materials leached from the CST. UOP personnel indicated to SRS personnel that these materials exist in the sorbent in excess ofmore » required stoichiometry. The authors examined the pretreatment of CST with sodium hydroxide to remove these components prior to placing the CST in radioactive service. Additionally, researchers analyzed solids discovered in the feed line during a test by non-destructive techniques.« less

Mineralogical and hydrochemical effects on adsorption removal of cesium-137 and strontium-90 by kaolinite.

PubMed

Jeong, C H

2001-01-01

Adsorption characteristics of the nuclides onto kaolinite were investigated by batch experiment under various pH conditions and concentrations of groundwater cations (Ca2+, Mg2+, K+ and Na+) and anions (HCO3-, CO3(2-) and SO4(2-). Adsorption removal of 137Cs and 90Sr by kaolinite greatly increased as the concentration of groundwater cations increased from 10(-5) to 10(-1) M. In contrast, the pH exerted a small effect on the adsorption of 137Cs and 90Sr onto kaolinite. The zeta potential of kaolinite particles showed a negative increase of amphoteric surface charge with increasing pH. The adsorption behavior of 90Sr was also highly dependent on the concentration of bicarbonate. The thermodynamic saturation index indicated that bicarbonate exerts great effect on strontium adsorption by the precipitation of a strontianite (SrCO3) and a change in pH.

Simulation of Sediment and Cesium Transport in the Ukedo River and the Ogi Dam Reservoir during a Rainfall Event using the TODAM Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishi, Yasuo; Yokuda, Satoru T.; Kurikami, Hiroshi

2014-03-28

The accident at the Fukushima Daiichi Nuclear Power Plant in March 2011 caused widespread environmental contamination. Although decontamination activities have been performed in residential areas of the Fukushima area, decontamination of forests, rivers, and reservoirs is still controversial because of the economical, ecological, and technical difficulties. Thus, an evaluation of contaminant transport in such an environment is important for safety assessment and for implementation of possible countermeasures to reduce radiation exposure to the public. The investigation revealed that heavy rainfall events play a significant role in transporting radioactive cesium deposited on the land surface, via soil erosion and sediment transportmore » in rivers. Therefore, we simulated the sediment and cesium transport in the Ukedo River and its tributaries in Fukushima Prefecture, including the Ogaki Dam Reservoir, and the Ogi Dam Reservoir of the Oginosawa River in Fukushima Prefecture during and after a heavy rainfall event by using the TODAM (Time-dependent, One-dimensional Degradation And Migration) code. The main outcomes are the following: • Suspended sand is mostly deposited on the river bottom. Suspended silt and clay, on the other hand, are hardly deposited in the Ukedo River and its tributaries except in the Ogaki Dam Reservoir in the Ukedo River even in low river discharge conditions. • Cesium migrates mainly during high river discharge periods during heavy rainfall events. Silt and clay play more important roles in cesium transport to the sea than sand does. • The simulation results explain variations in the field data on cesium distributions in the river. Additional field data currently being collected and further modeling with these data may shed more light on the cesium distribution variations. • Effects of 40-hour heavy rainfall events on clay and cesium transport continue for more than a month. This is because these reservoirs slow down the storm-induced high flow moving through these reservoirs. • The reservoirs play a major role as a sink of sediment and cesium in the river systems. Some amounts of sediment pass through them along with cesium in dissolved and clay-sorbed cesium forms. • Effects of countermeasures such as overland decontamination, dam control and sorbent injection were tentatively estimated. The simulation suggested that overland decontamination and sorbent injection would be effective for decreasing the contamination of water in the reservoir and in the river below the dam.« less

Two halide-containing cesium manganese vanadates: synthesis, characterization, and magnetic properties

DOE PAGES

Smith Pellizzeri, Tiffany M.; McGuire, Michael A.; McMillen, Colin D.; ...

2018-01-24

In this study, two new halide-containing cesium manganese vanadates have been synthesized by a high-temperature (580 °C) hydrothermal synthetic method from aqueous brine solutions. One compound, Cs 3Mn(VO 3) 4Cl, (1) was prepared using a mixed cesium hydroxide/chloride mineralizer, and crystallizes in the polar noncentrosymmetric space group Cmm2, with a = 16.7820(8) Å, b = 8.4765(4) Å, c = 5.7867(3) Å. This structure is built from sinusoidal zig-zag (VO 3) n chains that run along the b-axis and are coordinated to Mn 2+ containing (MnO 4Cl) square-pyramidal units that are linked together to form layers. The cesium cations reside betweenmore » the layers, but also coordinate to the chloride ion, forming a cesium chloride chain that also propagates along the b-axis. The other compound, Cs 2Mn(VO 3) 3F, (2) crystallizes in space group Pbca with a = 7.4286(2) Å, b = 15.0175(5) Å, c = 19.6957(7) Å, and was prepared using a cesium fluoride mineralizer. The structure is comprised of corner sharing octahedral Mn 2+ chains, with trans fluoride ligands acting as bridging units, whose ends are capped by (VO 3) n vanadate chains to form slabs. The cesium atoms reside between the manganese vanadate layers, and also play an integral part in the structure, forming a cesium fluoride chain that runs along the b-axis. Both compounds were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and single-crystal Raman spectroscopy. Additionally, the magnetic properties of 2 were investigated. Lastly, above 50 K, it displays behavior typical of a low dimensional system with antiferromagnetic interactions, as to be expected for linear chains of manganese(II) within the crystal structure.« less

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

PubMed

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.

Biological effects of cesium-137 injected in beagle dogs of different ages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C.

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 significantlymore » 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.« less

Synchrotron-Radiation Photoemission Study of Electronic Structures of a Cs-Doped Rubrene Surface

NASA Astrophysics Data System (ADS)

Cheng, Chiu-Ping; Lu, Meng-Han; Chu, Yu-Ya; Pi, Tun-Wen

Using synchrotron-radiation photoemission spectroscopy, we have studied the electronic structure of a cesium-doped rubrene thin film. The addition of cesium atoms causes the movement of the valence-band spectra and the change in line shapes at different concentration that can be separated into four different stages. In the first stage, the cesium atoms continuously diffuse into the substrate, and the Fermi level moves in the energy gap as a result of an electron transferred from the cesium to the rubrene. The second stage, in which the shifts of the spectra are interrupted, is characterized by the introduction of two in-gap states. When increasing doping of cesium into the third stage, the spectra move again; whereas, the line shapes maintain at the stoichiometric ratio of one. In the fourth stage, new in-gap states appear, which are the highest occupied molecular orbital (HOMO) and HOMO+1 states of (rubrene)2- anion.

Experimental and theoretical investigation for the suppression of the plasma arc drop in the thermionic converter

NASA Technical Reports Server (NTRS)

Shaw, D. T.; Manikopoulos, C. N.; Chang, T.; Lee, C. H.; Chiu, N.

1977-01-01

Ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter were studied. The decay of highly ionized cesium plasma was studied in the near afterglow to examine the recombination processes. Very low recombination in such a plasma may prove to be of considerable importance in practical converters. The approaches of external cesium generation were vibrationally excited nitrogen as an energy source of ionization of cesium ion, and microwave power as a means of resonant sustenance of the cesium plasma. Experimental data obtained so far show that all three techniques - i.e., the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave resonant cavity - can produce plasmas with their densities significantly higher than the Richardson density. The implication of these findings as related to Lam's theory is discussed.

Radiochemical determination of strontium-90 and cesium-137 in waters of the Pacific Ocean and its neighboring seas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borisenko, G.S.; Kandinskii, P.A.; Gedeonov, L.I.

1987-03-01

Depending on the salinity of the water, two versions of strontium-90 and cesium-137 concentration from water samples are presented. Cesium-137 was concentrated by precipitating sparingly soluble mixed hexacyanoferrates (II), and strontium-90 by precipitating carbonates together with calcium. A scheme has been given for radiochemical analysis of the concentrates. Strontium-90 and cesium-137 contents in the waters of the Pacific Ocean and its neighboring seas have been determined by the radiochemical method described. The levels of radionuclide content in the water and atmospheric precipitations have been shown to be inter-related. Strontium-90 and cesium-137 contents in the surface water of the northwestern Pacificmore » were found to be much lower in 1980 than in the early seventies. The area of technogenic radioactive pollution was found to persist in the region of the Columbia mouth into the Pacific Ocean.« less

Estimation of the Cesium-137 Source Term from the Fukushima Daiichi Power Plant Using Air Concentration and Deposition Data

NASA Astrophysics Data System (ADS)

Winiarek, Victor; Bocquet, Marc; Duhanyan, Nora; Roustan, Yelva; Saunier, Olivier; Mathieu, Anne

2013-04-01

A major difficulty when inverting the source term of an atmospheric tracer dispersion problem is the estimation of the prior errors: those of the atmospheric transport model, those ascribed to the representativeness of the measurements, the instrumental errors, and those attached to the prior knowledge on the variables one seeks to retrieve. In the case of an accidental release of pollutant, and specially in a situation of sparse observability, the reconstructed source is sensitive to these assumptions. This sensitivity makes the quality of the retrieval dependent on the methods used to model and estimate the prior errors of the inverse modeling scheme. In Winiarek et al. (2012), we proposed to use an estimation method for the errors' amplitude based on the maximum likelihood principle. Under semi-Gaussian assumptions, it takes into account, without approximation, the positivity assumption on the source. We applied the method to the estimation of the Fukushima Daiichi cesium-137 and iodine-131 source terms using activity concentrations in the air. The results were compared to an L-curve estimation technique, and to Desroziers's scheme. Additionally to the estimations of released activities, we provided related uncertainties (12 PBq with a std. of 15 - 20 % for cesium-137 and 190 - 380 PBq with a std. of 5 - 10 % for iodine-131). We also enlightened that, because of the low number of available observations (few hundreds) and even if orders of magnitude were consistent, the reconstructed activities significantly depended on the method used to estimate the prior errors. In order to use more data, we propose to extend the methods to the use of several data types, such as activity concentrations in the air and fallout measurements. The idea is to simultaneously estimate the prior errors related to each dataset, in order to fully exploit the information content of each one. Using the activity concentration measurements, but also daily fallout data from prefectures and cumulated deposition data over a region lying approximately 150 km around the nuclear power plant, we can use a few thousands of data in our inverse modeling algorithm to reconstruct the Cesium-137 source term. To improve the parameterization of removal processes, rainfall fields have also been corrected using outputs from the mesoscale meteorological model WRF and ground station rainfall data. As expected, the different methods yield closer results as the number of data increases. Reference : Winiarek, V., M. Bocquet, O. Saunier, A. Mathieu (2012), Estimation of errors in the inverse modeling of accidental release of atmospheric pollutant : Application to the reconstruction of the cesium-137 and iodine-131 source terms from the Fukushima Daiichi power plant, J. Geophys. Res., 117, D05122, doi:10.1029/2011JD016932.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.

This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. Itmore » was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.« less

Strontium-90 and cesium-137 distribution in Baltic Sea waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarev, L.N.; Gedeonov, L.I.; Ivanova, L.M.

The strontium-90 and cesium-137 concentrations determined in 1983 in the Baltic Sea proper and the Gulf of Finland and in the Soviet Baltic rivers are furnished. The cesium-137 content has been found to be directly proportional to the salinity of the water. Significant influx of technogenic radioactive contaminants from the North to the Baltic Sea was noted in 1983.

Introduction to Quartz Frequency Standards

DTIC Science & Technology

1992-03-01

changes is 5 X 10-"N. Gas permeation under conditions where there is an abnormally high concentration of hydrogen or helium in the atmosphere can lead...Rubidium Life Rubidium depletion Power Buffer gas depletion __________Weight Glass contaminants Cesium Life Cesium supply depletion Power Spent cesium... Tifton , R., Electronic Activity Dip Measurement, IEEE Trans. on Instrumentation and Measurement, Vol. IM-27, pp. 59-65, 1978. 23. Ballato, A., Frequency

Human cytomegalovirus renders cells non-permissive for replication of herpes simplex viruses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cockley, K.D.

1988-01-01

The herpes simplex virus (HSV) genome during production infection in vitro may be subject to negative regulation which results in modification of the cascade of expression of herpes virus macromolecular synthesis leading to establishment of HSV latency. In the present study, human embryonic lung (HEL) cells infected with human cytomegalovirus (HCMV) restricted the replication of HSV type-1 (HSV-1). A delay in HSV replication of 15 hr as well as a consistent, almost 1000-fold inhibition of HSV replication in HCMV-infected cell cultures harvested 24 to 72 hr after superinfection were observed compared with controls infected with HSV alone. HSV type-2 (HSV-2)more » replication was similarly inhibited in HCMV-infected HEL cells. Prior ultraviolet-irradiation (UV) of HCMV removed the block to HSV replication, demonstrating the requirement for an active HCMV genome. HCMV deoxyribonucleic acid (DNA) negative temperature-sensitive (ts) mutants inhibited HSV replications as efficiently as wild-type (wt) HCMV at the non-permissive temperature. Evidence for penetration and replication of superinfecting HSV into HCMV-infected cells was provided by blot hybridization of HSV DNA synthesized in HSV-superinfected cell cultures and by cesium chloride density gradient analysis of ({sup 3}H)-labeled HSV-1-superinfected cells.« less

Work function measurements during plasma exposition at conditions relevant in negative ion sources for the ITER neutral beam injection.

PubMed

Gutser, R; Wimmer, C; Fantz, U

2011-02-01

Cesium seeded sources for surface generated negative hydrogen ions are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER. The stability and delivered current density depend highly on the work function during vacuum and plasma phases of the ion source. One of the most important quantities that affect the source performance is the work function. A modified photocurrent method was developed to measure the temporal behavior of the work function during and after cesium evaporation. The investigation of cesium exposed Mo and MoLa samples under ITER negative hydrogen ion based neutral beam injection relevant surface and plasma conditions showed the influence of impurities which result in a fast degradation when the plasma exposure or the cesium flux onto the sample is stopped. A minimum work function close to that of bulk cesium was obtained under the influence of the plasma exposition, while a significantly higher work function was observed under ITER-like vacuum conditions.

Thermionic converter performance with oxide collectors

NASA Technical Reports Server (NTRS)

Lieb, D.; Goodale, D.; Briere, T.; Balestra, C.

1977-01-01

Thermionic converters using a variety of metal oxide collector surfaces have been fabricated and tested. Both work function and power output data are presented and evaluated. Oxides of barium, strontium, zinc, tungsten and titanium have been incorporated into a variable spacing converter. Tungsten oxide was found to give the highest converter performance and to furnish oxygen for the emitter at the same time. Oxygenated emitters operate at reduced cesium pressure with an increase in electrode spacing. Electron spectroscopy for chemical analysis (ESCA) performed on several tungsten oxide collectors showed cesium penetration of the oxide layer, possibly forming a cesium tungstate bronze. Titanium oxide showed high performance but did not furnish oxygen for the emitter; strontium oxide, in the form of a sprayed layer, appeared to dissociate in the presence of cesium. Sprayed coatings of barium and zinc oxides produced collector work functions of about 1.3 eV, but had excessive series resistance. Lanthanum hexaboride, in combination with oxygen introduced through a silver tube, and cesium produced a low work function collector and better than average performance.

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

PubMed

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.

Highly-efficient quantum memory for polarization qubits in a spatially-multiplexed cold atomic ensemble.

PubMed

Vernaz-Gris, Pierre; Huang, Kun; Cao, Mingtao; Sheremet, Alexandra S; Laurat, Julien

2018-01-25

Quantum memory for flying optical qubits is a key enabler for a wide range of applications in quantum information. A critical figure of merit is the overall storage and retrieval efficiency. So far, despite the recent achievements of efficient memories for light pulses, the storage of qubits has suffered from limited efficiency. Here we report on a quantum memory for polarization qubits that combines an average conditional fidelity above 99% and efficiency around 68%, thereby demonstrating a reversible qubit mapping where more information is retrieved than lost. The qubits are encoded with weak coherent states at the single-photon level and the memory is based on electromagnetically-induced transparency in an elongated laser-cooled ensemble of cesium atoms, spatially multiplexed for dual-rail storage. This implementation preserves high optical depth on both rails, without compromise between multiplexing and storage efficiency. Our work provides an efficient node for future tests of quantum network functionalities and advanced photonic circuits.

Simulating Wet Deposition of Radiocesium from the Chernobyl Accident

DTIC Science & Technology

2001-03-01

In response to the Chernobyl nuclear power plant accident of 1986, a cesium-137 deposition dataset was assembled. Most of the airborne Chernobyl ... Chernobyl cesium-137. A cloud base parameterization modification is tested and appears to slightly improve the accuracy of one HYSPLIT simulation of...daily Chernobyl cesium-137 deposition over the course of the accident at isolated European sites, and degrades the accuracy of another HYSPLIT simulation

Mid-Award Progress Report for Department of Energy Office of Science Graduate Student Research Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, M. K.

The purpose of the work proposed for this study is to investigate the behavior and transport mechanisms for cesium-137 in soils collected from contaminated sites with distinct source release scenarios. More specifically, this study aims to determine with which elements and minerals cesium-137 associates in these various environments to more reliably predict its migration in the subsurface. This will be achieved using a state-of-the-art analysis technique available at Lawrence Livermore National Laboratory (LLNL) known as NanoSIMS. Nano-scale secondary ion mass spectrometry, or NanoSIMS, is a destructive surface analysis technique in which positive secondary ions are generated from the surface ofmore » a sample and then quantified based on their mass-to-charge ratio (m/z) using mass spectrometry. The data collected about the secondary ions can then be used to create isotope-specific spatial maps with a resolution of a few hundred nanometers and depth profiles that show the variation of the secondary ion intensity with sputtering time. This should be an ideal technique for locating cesium-137 in a sample, as cesium is an easily ionized element, meaning the yield of secondary cesium (Cs) ions produced should be high and making the identification of cesium-137 straight forward.« less

Quantifying Atmospheric Fallout of Fukushima-derived Radioactive Isotopes in the Hawaiian Islands

NASA Astrophysics Data System (ADS)

McKenzie, Trista; Dulai, Henrietta

2016-04-01

On March 11, 2011, several reactors at the Fukushima Dai-ichi Nuclear Power Plant suffered damage and released the radioisotopes iodine-131, cesium-134, and cesium-137 into the atmosphere. A week later, these isotopes were detected in aerosols over the state of Hawaii and in milk samples analyzed from the Big Island. Because the detected levels were significantly below levels of health concern, the state did not attempt to quantify the deposition of these nuclides on the islands. This study estimated the magnitude of atmospheric fallout of cesium and iodine, and examined the patterns of cesium wet deposition with precipitation observed in March 2011. Mushroom and soil samples were collected along precipitation gradients on Oahu and the island of Hawaii and analyzed for cesium isotopes using gamma spectrometry. Fukushima-derived fallout was differentiated from historic nuclear weapons testing fallout by the presence of Cs-134, which has a shorter half-life of 2.06 years and the fact that Cs-134 and 137 were released from the severed power plant nearly in parity. We found that Fukushima-derived cesium was present in both mushrooms and soil and the soil inventories ranged 2.2-60.9 Bq/m2 for Cs-137 and 16.1-445.8 Bq/m2 for I-131. Additionally, we found that Fukushima-derived cesium inventories in soils were correlated with precipitation gradients. This research confirmed and quantified the presence of Fukushima-derived fallout in Hawaii, however the activities detected were orders of magnitude lower than fallout associated with the nuclear weapons testing in the Pacific.

An accurate derivation of the air dose-rate and the deposition concentration distribution by aerial monitoring in a low level contaminated area

NASA Astrophysics Data System (ADS)

Nishizawa, Yukiyasu; Sugita, Takeshi; Sanada, Yukihisa; Torii, Tatsuo

2015-04-01

Since 2011, MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan) have been conducting aerial monitoring to investigate the distribution of radioactive cesium dispersed into the atmosphere after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), Tokyo Electric Power Company. Distribution maps of the air dose-rate at 1 m above the ground and the radioactive cesium deposition concentration on the ground are prepared using spectrum obtained by aerial monitoring. The radioactive cesium deposition is derived from its dose rate, which is calculated by excluding the dose rate of the background radiation due to natural radionuclides from the air dose-rate at 1 m above the ground. The first step of the current method of calculating the dose rate due to natural radionuclides is calculate the ratio of the total count rate of areas where no radioactive cesium is detected and the count rate of regions with energy levels of 1,400 keV or higher (BG-Index). Next, calculate the air dose rate of radioactive cesium by multiplying the BG-Index and the integrated count rate of 1,400 keV or higher for the area where the radioactive cesium is distributed. In high dose-rate areas, however, the count rate of the 1,365-keV peak of Cs-134, though small, is included in the integrated count rate of 1,400 keV or higher, which could cause an overestimation of the air dose rate of natural radionuclides. We developed a method for accurately evaluating the distribution maps of natural air dose-rate by excluding the effect of radioactive cesium, even in contaminated areas, and obtained the accurate air dose-rate map attributed the radioactive cesium deposition on the ground. Furthermore, the natural dose-rate distribution throughout Japan has been obtained by this method.

Engineering high charge transfer n-doping of graphene electrodes and its application to organic electronics.

PubMed

Sanders, Simon; Cabrero-Vilatela, Andrea; Kidambi, Piran R; Alexander-Webber, Jack A; Weijtens, Christ; Braeuninger-Weimer, Philipp; Aria, Adrianus I; Qasim, Malik M; Wilkinson, Timothy D; Robertson, John; Hofmann, Stephan; Meyer, Jens

2015-08-14

Using thermally evaporated cesium carbonate (Cs2CO3) in an organic matrix, we present a novel strategy for efficient n-doping of monolayer graphene and a ∼90% reduction in its sheet resistance to ∼250 Ohm sq(-1). Photoemission spectroscopy confirms the presence of a large interface dipole of ∼0.9 eV between graphene and the Cs2CO3/organic matrix. This leads to a strong charge transfer based doping of graphene with a Fermi level shift of ∼1.0 eV. Using this approach we demonstrate efficient, standard industrial manufacturing process compatible graphene-based inverted organic light emitting diodes on glass and flexible substrates with efficiencies comparable to those of state-of-the-art ITO based devices.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles. [energy conversion efficiency in electric power plants

NASA Technical Reports Server (NTRS)

Deegan, P. B.

1976-01-01

Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh).

10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2012 CFR

2012-01-01

... Iodine-126 1 Iodine-129 0.1 Iodine-131 1 Iodine-132 10 Iodine-133 1 Iodine-134 10 Iodine-135 10 Iridium... Arsenic-73 100 Arsenic-74 10 Arsenic-76 10 Arsenic-77 100 Barium-131 10 Barium-133 10 Barium-140 10... Carbon-14 100 Cerium-141 100 Cerium-143 100 Cerium-144 1 Cesium-131 1,000 Cesium-134m 100 Cesium-134 1...

10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2014 CFR

2014-01-01

... Iodine-126 1 Iodine-129 0.1 Iodine-131 1 Iodine-132 10 Iodine-133 1 Iodine-134 10 Iodine-135 10 Iridium... Arsenic-73 100 Arsenic-74 10 Arsenic-76 10 Arsenic-77 100 Barium-131 10 Barium-133 10 Barium-140 10... Carbon-14 100 Cerium-141 100 Cerium-143 100 Cerium-144 1 Cesium-131 1,000 Cesium-134m 100 Cesium-134 1...

10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2013 CFR

2013-01-01

... Iodine-126 1 Iodine-129 0.1 Iodine-131 1 Iodine-132 10 Iodine-133 1 Iodine-134 10 Iodine-135 10 Iridium... Arsenic-73 100 Arsenic-74 10 Arsenic-76 10 Arsenic-77 100 Barium-131 10 Barium-133 10 Barium-140 10... Carbon-14 100 Cerium-141 100 Cerium-143 100 Cerium-144 1 Cesium-131 1,000 Cesium-134m 100 Cesium-134 1...

Cesium Platinide Hydride 4Cs 2 Pt-CsH: An Intermetallic Double Salt Featuring Metal Anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smetana, Volodymyr; Mudring, Anja-Verena

2016-10-24

With Cs9Pt4H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs 9Pt 4H exhibits a complex crystal structure containing Cs + cations, Pt 2- and H - anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the “alloy” cesium–platinum, or better cesium platinide, Cs2Pt, and the salt cesium hydride CsH according to Cs 9Pt 4H≡4 Cs 2Pt∙CsH.

Fabrication and surface characterization of composite refractory compounds suitable for thermionic converters

NASA Technical Reports Server (NTRS)

Davis, P. R.; Swanson, L. W.

1980-01-01

Thermal faceting was observed for the high index planes of LaB6. The (100), (110), and (111) planes were found to be the most thermodynamically stable faces in vacuum in a study of electrode materials for thermionic emitters. The properties of adsorbed carbon, cesium, and cesium-oxygen layers were investigated on LaB6 single crystal surfaces as well as on Zr/0/W(100) and W(100). Cesium was found to increase electron reflection near the collision threshold on LaB6(100) and W(100) and to decrease the reflection on Zr/0/W(100). This difference may be explained by the unusually high threshold reflection coefficient of Zr/0/W without adsorbed cesium.

Lanthanide doped strontium-barium cesium halide scintillators

DOEpatents

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.

Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

DOE PAGES

Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; ...

2016-03-17

Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 ( 137Cs) and xenon-133 ( 133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to theirmore » available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τ e, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95 % confidence interval 13.1–15.7 days). The equivalent modelled τ e lifetimes have a large spread, varying between 4.8 and 26.7 days with a model median of 9.4 ± 2.3 days, indicating too fast a removal in most models. Because sufficient measurement data were only available from about 2 weeks after the release, the estimated lifetimes apply to aerosols that have undergone long-range transport, i.e. not for freshly emitted aerosol. However, modelled instantaneous lifetimes show that the initial removal in the first 2 weeks was quicker (lifetimes between 1 and 5 days) due to the emissions occurring at low altitudes and co-location of the fresh plume with strong precipitation. Deviations between measured and modelled aerosol lifetimes are largest for the northernmost stations and at later time periods, suggesting that models do not transport enough of the aerosol towards the Arctic. The models underestimate passive tracer ( 133Xe) concentrations in the Arctic as well but to a smaller extent than for the aerosol ( 137Cs) tracer. As a result, this indicates that in addition to too fast an aerosol removal in the models, errors in simulated atmospheric transport towards the Arctic in most models also contribute to the underestimation of the Arctic aerosol concentrations.« less

Evaluation of Observed and Modelled Aerosol Lifetimes Using Radioactive Tracers of Opportunity and an Ensemble of 19 Global Models

NASA Technical Reports Server (NTRS)

Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; Croft, B.; Sovde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.;

Multiscale Modeling of Radioisotope Transfers in Watersheds, Rivers, Reservoirs and Ponds of Fukushima Prefecture

NASA Astrophysics Data System (ADS)

Zheleznyak, M.; Kivva, S.; Nanba, K.; Wakiyama, Y.; Konoplev, A.; Onda, Y.; Gallego, E.; Papush, L.; Maderych, V.

2015-12-01

The highest densities of the radioisotopes in fallout from the Fukushima Daiichi NPP in March 2011 were measured at the north eastern part of Fukushima Prefecture. The post-accidental aquatic transfer of cesium -134/137 includes multiscale processes: wash-off from the watersheds in solute and with the eroded soil, long-range transport in the rivers, deposition and resuspension of contaminated sediments in reservoirs and floodplains. The models of EU decision support system RODOS are used for predicting dynamics of 137Cs in the Fukushima surface waters and for assessing efficiency of the remediation measures. The transfer of 137Cs through the watershed of Niida River was simulated by DHSVM -R model that includes the modified code of the distributed hydrological and sediment transport model DHSVM (Lettenmayer, Wigmosta et al.) and new module of radionuclide transport. DHSMV-R was tested by modelling the wash-off from the USLE experimental plots in Fukushima prefecture. The model helps to quantify the influence of the differentiators of Fukushima and Chernobyl watersheds, - intensity of extreme precipitation and steepness of watershed, on the much higher values of the ratio "particulated cesium /soluted cesium" in Fukushima rivers than in Chernobyl rivers. Two dimensional model COASTOX and three dimensional model THREETOX are used to simulate the fate of 137Cs in water and sediments of reservoirs in the Manogawa River, Otagawa River, Mizunashigawa River, which transport 137Cs from the heavy contaminated watersheds to the populated areas at the Pacific coast. The modeling of the extreme floods generated by typhoons shows the resuspension of the bottom sediments from the heavy contaminated areas in reservoirs at the mouths of inflowing rivers at the peaks of floods and then re-deposition of 137Cs downstream in the deeper areas. The forecasts of 137Cs dynamics in bottom sediments of the reservoirs were calculated for the set of the scenarios of the sequences of the high floods of the next years. MOIRA -LAKE model of long term radioisotopes transfer in water, bottom sediment and fish was used for the assessments of the efficiency of the bottom sediment dredging for the remediation of the irrigation ponds at Okuma town.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Garrett N.; Russell, Renee L.; Peterson, Reid A.

This report summarizes the work performed to evaluate multiple, cesium loading, and elution cycles for small columns containing SRF resin using a simple, high-level waste (HLW) simulant. Cesium ion exchange loading and elution curves were generated for a nominal 5 M Na, 2.4E-05 M Cs, 0.115 M Al loading solution traced with 134Cs followed by elution with variable HNO3 (0.02, 0.07, 0.15, 0.23, and 0.28 M) containing variable CsNO3 (5.0E-09, 5.0E-08, and 5.0E-07 M) and traced with 137Cs. The ion exchange system consisted of a pump, tubing, process solutions, and a single, small ({approx}15.7 mL) bed of SRF resin withmore » a water-jacketed column for temperature-control. The columns were loaded with approximately 250 bed volumes (BVs) of feed solution at 45 C and at 1.5 to 12 BV per hour (0.15 to 1.2 cm/min). The columns were then eluted with 29+ BVs of HNO3 processed at 25 C and at 1.4 BV/h. The two independent tracers allowed analysis of the on-column cesium interaction between the loading and elution solutions. The objective of these tests was to improve the correlation between the spent resin cesium content and cesium leached out of the resin in subsequent loading cycles (cesium leakage) to help establish acid strength and purity requirements.« less

Radioactive and Stable Cesium Distributions in Fukushima Forests

NASA Astrophysics Data System (ADS)

Ioshchenko, V.; Kivva, S.; Konoplev, A.; Nanba, K.; Onda, Y.; Takase, T.; Zheleznyak, M.

2015-12-01

Fukushima Dai-ichi NPP accident has resulted in release into the environment of large amounts of 134Cs and 137Cs and in radioactive contamination of terrestrial and aquatic ecosystems. In Fukushima prefecture up to 2/3 of the most contaminated territory is covered with forests, and understanding of its further fate in the forest ecosystems is essential for elaboration of the long-term forestry strategy. At the early stage, radiocesium was intercepted by the trees' canopies. Numerous studies reported redistribution of the initial fallout in Fukushima forests in the followed period due to litterfall and leaching of radiocesium from the foliage with precipitations. By now these processes have transported the major part of deposited radiocesium to litter and soil compartments. Future levels of radiocesium activities in the aboveground biomass will depend on relative efficiencies of the radiocesium root uptake and its return to the soil surface with litterfall and precipitations. Radiocesium soil-to-plant transfer factors for typical tree species, soil types and landscape conditions of Fukushima prefecture have not been studied well; moreover, they may change in time with approaching to the equilibrium between radioactive and stable cesium isotopes in the ecosystem. The present paper reports the results of several ongoing projects carried out by Institute of Environmental Radioactivity of Fukushima University at the experimental sites in Fukushima prefecture. For typical Japanese cedar (Cryptomeria japonica) forest, we determined distributions of radiocesium in the ecosystem and in the aboveground biomass compartments by the end of 2014; available results for 2015 are presented, too, as well as the results of test application of D-shuttle dosimeters for characterization of seasonal variations of radiocesium activity in wood. Based on the radiocesium activities in biomass we derived the upper estimates of its incorporation and root uptake fluxes, 0.7% and 3% of the total inventory in the ecosystem. Measurements of stable cesium concentrations in the biomass compartments enabled obtaining the more precise estimates. Return fluxes of both radioactive and stable cesium also were quantified, which forms the basis for modelling of the long-term redistribution of radiocesium in the studied ecosystem.

A study of environmental effects caused by cesium from ion thrusters

NASA Technical Reports Server (NTRS)

1971-01-01

The ATS-F satellite will carry two cesium ion thrusters. Cesium is a material that is not present in the upper atmosphere, and there is concern that the introduction of this material may result in some unexpected behavior. A study has been conducted to assess the magnitude of the effects that are to be expected. No observable effects were found as a result of the study. Consideration was given to the origin and destination of the material and the various reactions that could occur. The origin was considered to be anywhere in space from altitudes of about 100 km upward. The probable short term destination is in the form of cesium ions trapped in the earth's magnetic field or as ions and atoms in the heterosphere. The maximum possible number of cesium atoms in the field of view of an earth based observer is of the order of one million per square centimeter, far too few to be observable by visible, near-visible, or radio-frequency means. Further, no phenomena could be found that would result in the occurance of an observable event.

RECOVERY OF CESIUM FROM WASTE SOLUTIONS

DOEpatents

Burgus, W.H.

1959-06-30

This patent covers the precipitation of fission products including cesium on nickel or ferric ferrocyanide and subsequent selective dissolution from the carrier with a solution of ammonia or mercurlc nitrate.

Transport of the radioisotopes iodine-131, cesium-134, and cesium-137 from the fallout following the accident at the Chernobyl nuclear reactor into cheesemaking products.

PubMed

Assimakopoulos, P A; Ioannides, K G; Pakou, A A; Papadopoulou, C V; Paradopoulou, C V

1987-07-01

The transport of radiation contamination from milk to products of the cheese making process has been studied. The concentration of radioactive iodine and cesium in samples of sheep milk and cheese (Gruyère) products was measured for 10 consecutive production d. Milk with concentration 100 Bq/L in each of the radionuclides 131I, 134Cs, and 137Cs cheese with concentration 82.2 +/- 3.9 Bq/kg in iodine and an average of 42.3 +/- 2.3 Bq/kg in the cesium isotopes is produced. The corresponding concentrations in cream extracted from the same milk are 26.7 +/- 2.8 Bq/kg (131I) and 18.6 +/- 1.9 Bq/kg (134Cs, 137Cs).

Mass selective separation applied to radioisotopes of cesium: Mass selective applied to radioisotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dion, Michael; Eiden, Greg; Farmer, Orville

2016-07-22

A developed technique that uses the intrinsic mass-based separation capability of a quadrupole mass spectrometer has been used to resolve spectral radiometric interference of two isotopes of the same element. In this work the starting sample was a combination of 137Cs and 134Cs and was (activity) dominated by 137Cs and this methodology separated and “implanted” 134Cs that was later quantified for spectral features and ac- tivity with traditional radiometric techniques. This work demonstrated a 134Cs/137Cs activity ratio enhancement of >4 orders of magnitude and complete removal of 137Cs spectral features from the implanted target mass (i.e., 134).

RADIATION SOURCES

DOEpatents

Brucer, M.H.

1958-04-15

A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

The uptake and elimination of cesium-137 by a grasshopper-romalea microptera

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crossley, Jr, D A; Pryor, M E

1960-10-01

Adults of Romalea microptera, the eastern lubber grasshopper, were fed cesium-137 in bean plants to investigate uptake and elimination of this isotope. A biological half-life of 4 to 5 days was obtained. In experiments where grasshoppers were allowed to feed repeatedly on cesium-contaminated food, the biological half-life was used to pretend Cs 137 was concentrated in muscular tissue, but some was also found in the digestive tract and reproductive organs. Only trace amounts were found in the exoskeleton.

Small-angle neutron scattering study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and cesium dodecyl sulfate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajewska, A., E-mail: aldonar@jinr.ru; Medrzycka, K.; Hallmann, E.

2016-01-15

The micellization in mixed aqueous systems based on a nonionic surfactant, heptaethylene glycol monotetradecyl ether (C{sub 14}E{sub 7}), and an anionic surfactant, cesium dodecyl sulfate, has been investigated by small-angle neutron scattering. Preliminary data on the behavior of the C{sub 14}E{sub 7} aqueous solutions (with three concentrations, 0.17, 0.5, and 1%) mixed with a small amount of anionic surfactant, cesium dodecyl sulfate, are reported.

Continuous-flow stirred-tank reactor 20-L demonstration test: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, D.D.; Collins, J.L.

One of the proposed methods of removing the cesium, strontium, and transuranics from the radioactive waste storage tanks at Savannah River is the small-tank tetraphenylborate (TPB) precipitation process. A two-reactor-in-series (15-L working volume each) continuous-flow stirred-tank reactor (CSTR) system was designed, constructed, and installed in a hot cell to test the Savannah River process. The system also includes two cross-flow filtration systems to concentrate and wash the slurry produced in the process, which contains the bulk of radioactivity from the supernatant processed through the system. Installation, operational readiness reviews, and system preparation and testing were completed. The first test usingmore » the filtration systems, two CSTRs, and the slurry concentration system was conducted over a 61-h period with design removal of Cs, Sr, and U achieved. With the successful completion of Test 1a, the following tests, 1b and 1c, were not required.« less

DEMETERRES project: development of innovative technologies for removing radionuclides from contaminated solid and liquid matrices

NASA Astrophysics Data System (ADS)

Chagvardieff, Pierre; Barré, Yves; Blin, Virginie; Faure, Sylvain; Fornier, Anne; Grange, Didier; Grandjean, Agnès; Guiderdoni, Emmanuel; Henner, Pascale; Siroux, Brice; Leybros, Antoine; Messalier, Marc; Paillard, Hervé; Prévost, Thierry; Rennesson, Malvina; Sarrobert, Catherine; Vavasseur, Alain; Véry, Anne-Aliénor

2017-09-01

As part of the « post-accidental » management, the DEMETERRES project (RSNR PIA) proposes to develop innovative and environmentally friendly methods for removal of cesium and strontium from soils and liquid matrices in order to rehabilitate them for an agricultural use while minimizing the volume of generated wastes in accordance with the nuclear waste existing processes. Complementary approaches are used: they are based on physico-chemical technologies (such as foams flotation, supercritical CO2 extraction, extractants in fluidized bed reactor …) and biological ones (bioextractants, phytoextraction) which concepts are described. These researches aim to design innovative and performing extractants in term of selectivity and to achieve the pilot reactor phase for each of them. These pilots will group in a network to provide a technological platform lasting the project, to which will be attached an available network of experts. The respective advances of these researches are presented, completed of tests initiated in Japan on contaminated soils through partnerships.

Preliminary Three-Dimensional Simulation of Sediment and Cesium Transport in the Ogi Dam Reservoir using FLESCOT – Task 6, Subtask 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishi, Yasuo; Kurikami, Hiroshi; Yokuda, Satoru T.

2014-03-28

After the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, the Japan Atomic Energy Agency and the Pacific Northwest National Laboratory initiated a collaborative project on environmental restoration. In October 2013, the collaborative team started a task of three-dimensional modeling of sediment and cesium transport in the Fukushima environment using the FLESCOT (Flow, Energy, Salinity, Sediment Contaminant Transport) code. As the first trial, we applied it to the Ogi Dam Reservoir that is one of the reservoirs in the Japan Atomic Energy Agency’s (JAEA’s) investigation project. Three simulation cases under the following different temperature conditions were studied:more » • incoming rivers and the Ogi Dam Reservoir have the same water temperature • incoming rivers have lower water temperature than that of the reservoir • incoming rivers have higher water temperature than that of the reservoir. The preliminary simulations suggest that seasonal temperature changes influence the sediment and cesium transport. The preliminary results showed the following: • Suspended sand, and cesium adsorbed by sand, coming into the reservoirs from upstream rivers is deposited near the reservoir entrance. • Suspended silt, and cesium adsorbed by silt, is deposited farther in the reservoir. • Suspended clay, and cesium adsorbed by clay, travels the farthest into the reservoir. With sufficient time, the dissolved cesium reaches the downstream end of the reservoir. This preliminary modeling also suggests the possibility of a suitable dam operation to control the cesium migration farther downstream from the dam. JAEA has been sampling in the Ogi Dam Reservoir, but these data were not yet available for the current model calibration and validation for this reservoir. Nonetheless these preliminary FLESCOT modeling results were qualitatively valid and confirmed the applicability of the FLESCOT code to the Ogi Dam Reservoir, and in general to other reservoirs in the Fukushima environment. The issues to be addressed in future are the following: • Validate the simulation results by comparison with the investigation data. • Confirm the applicability of the FLESCOT code to Fukushima coastal areas. • Increase computation speed by parallelizing the FLESCOT code.« less

Cesium iodide crystals fused to vacuum tube faceplates

NASA Technical Reports Server (NTRS)

Fleck, H. G.

1964-01-01

A cesium iodide crystal is fused to the lithium fluoride faceplate of a photon scintillator image tube. The conventional silver chloride solder is then used to attach the faceplate to the metal support.

Radionuclides in Foods

PubMed Central

Bird, P. M.

1966-01-01

Levels of strontium-90 and cesium-137 in Canadian milk during the period 1960-64 were consistently higher than those in the United States or the United Kingdom, but levels in humans, while also higher, did not reflect the differences observed in milk. Annual dose rates of 27 millirads to bone and 4 millirads to the whole body correspond to the highest average concentrations of strontium-90 and cesium-137 so far observed. Levels of cesium-137 in the urine of residents of the Canadian North were found to increase with the increasing consumption of caribou or reindeer. Whole body counting of a few northern residents showed cesium-137 levels as high as 1000 nanocuries. It is concluded that protective actions are not needed but that studies in the North should be emphasized to provide a better basis for evaluating that particular situation. PMID:5948368

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, T F

Rongelap Atoll experienced close-in ''local fallout'' from nuclear weapons tests conducted by the United States (1946-58) in the northern Marshall Islands. Most of the radiation dose delivered to Rongelap Island residents during the 1950s was from radioactive elements that quickly decayed into non-radioactive elements. Since 1985, the Lawrence Livermore National Laboratory (LLNL) has continued to provide monitoring of radioactive elements from bomb testing in the terrestrial and marine environment of Rongelap Atoll. The only remaining radioactive elements of environmental importance at the atoll are radioactive cesium (cesium-137), radioactive strontium (strontium-90), different types (isotopes) of plutonium, and americium (americium-241). Cesium- 137more » and strontium-90 dissolve in seawater and are continually flushed out of the lagoon into the open ocean. The small amount of residual radioactivity from nuclear weapons tests remaining in the lagoon does not concentrate through the marine food chain. Elevated levels of cesium-137 and strontium-90 are still present in island soils and pose a potential health risk if certain types of local plants and coconut crabs are eaten in large quantities. Cesium-137 is taken up from the soil into plants and edible food products, and may end up in the body of people living on the islands and consuming local food. The presence of cesium-137 in the human body can be detected using a device called a whole body counter. A person relaxes in a chair for a few minutes while counts or measurements are taken using a detector a few inches away from the body. The whole body counting program on Rongelap Island was established in 1999 under a cooperative agreement between the Rongelap Atoll Local Government (RALG), the Republic of the Marshall Islands and the U.S. Department of Energy (DOE). Local technicians from Rongelap continue to operate the facility under supervision of scientists from LLNL. The facility permits resettlement workers living on Rongelap Island to check the amount of cesium-137 in their bodies. The amount of cesium-137 detected in resettlement workers living on Rongelap Island over the past three years is well below the level of radiation exposure considered safe by the Nuclear Claims Tribunal. Returning residents and visitors to Rongelap will also be able to receive a whole body count free of charge to check the level of cesium in their bodies. There is also a very low health risk from exposure to external sources of radiation from visiting or walking around any of the islands on the atoll.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaminski, Michael D.; Mertz, Carol J.

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/cm 3. 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 saltmore » 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.« less

Distribution of radioactive cesium in edible parts of cattle.

PubMed

Okada, Keiji; Sato, Itaru; Deguchi, Yoshitaka; Morita, Shigeru; Yasue, Takeshi; Yayota, Masato; Takeda, Ken-Ichi; Sato, Shusuke

2013-12-01

After the disastrous incident of the Fukushima Daiichi Nuclear Power Station, various agricultural, livestock and fishery products have been inspected for radioactive contamination with cesium in Japan. In this study, radioactive cesium was measured in various edible parts of cattle to verify the current inspection method for cattle, in which the neck tissues are generally used as samples. Radioactive cesium concentration in the short plate, diaphragm, liver, lung, omasum, abomasum and small intestine were lower and sirloin, tenderloin, top round meat and tongue were higher than that in the neck. There was no significant difference between the other organs (heart, kidney, lumen and reticulum) and the neck. Ninety-five percent upper tolerance limits of the relative concentration to the neck were 1.88 for sirloin, 1.74 for tenderloin, 1.87 for top round and 1.45 for tongue. These results suggest that a safety factor of 2 is recommended for the radioactivity inspection of cattle to prevent a marketing of meat with higher cesium than the legal limit. Re-inspection should be conducted using another part of muscle, for example, top round, when suspicious levels of 50-100 Bq/kg are detected in the neck. © 2013 Japanese Society of Animal Science.

Rocksalt or cesium chloride: Investigating the relative stability of the cesium halide structures with random phase approximation based methods

NASA Astrophysics Data System (ADS)

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.

Recent developments in nanostructured inorganic materials for sorption of cesium and strontium: Synthesis and shaping, sorption capacity, mechanisms, and selectivity-A review.

PubMed

Alby, Delhia; Charnay, Clarence; Heran, Marc; Prelot, Bénédicte; Zajac, Jerzy

2018-02-15

Liquid wastes containing non-ferrous heavy metal ions and some radionuclides, 137 Cs and 90 Sr in particular, represent one of the most dangerous sources of environmental contamination. The remediation of wastewater containing such pollutants continue to be among the biggest challenges of Sustainable Development and Environmental Safety. Sorption-based technologies have proven their efficiency also in reducing the radionuclide content in aqueous streams to low-level residual activity, with the concomitant decrease in the amount of ultimate solid waste generated. Although sorption of cesium and strontium by resins, clays, and zeolites has been investigated intensively and even used in real applications, there is still considerable scope for improvement in terms of retention capacity and selectivity. Recent progress in design and preparation of nanostructured inorganic materials has attracted growing interest based on the potential for improving the retention performance when coupling such functionalities as ion exchange capacity, structural flexibility that may result in steric retention effects, as well as the propensity to interact specifically with the target metal cations. Titanate, vanadate, and tungsten based materials, manganese oxides, hexacyanoferrates, metal sulfides, ammonium molybdophosphates, or hydroxyapatite, characterized by various structures and morphologies, are reviewed with the emphasis being put on synthesis and shaping of such materials, their structure in relationship with the capacity and selectivity of trapping cesium and strontium from either single or multi-component aqueous solutions, as well as the possible retention mechanism. The potential candidates for remediation uses are selected with regard to their sorption capacity and distribution coefficient towards target cations, and also the pH window for an optimum cation capture. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the adsorptive behavior of cesium and strontium on hydroxyapatite and zeolite for decontamination of radioactive substances.

PubMed

Ozeki, K; Aoki, H

2016-08-12

Removal of radioactive substances, such as cesium (Cs) and strontium (Sr), has become an emerging issue after the Fukushima Daiichi Nuclear Power Plant Disaster. To assess the possibility that hydroxyapatite (HA) and zeolites can be used for removal of radioactive substances, the adsorption capacities of Cs and Sr on the HA and a zeolite were investigated. The influence of Fe ions on Cs and Sr adsorption on the HA and the zeolite was also evaluated, because Fe ions are the most effective inhibitor of Cs adsorption on the zeolite.In the Cs adsorption process on the HA and the zeolite, the zeolite showed a higher adsorption ratio than the HA, and the maximum sorption capacity of the zeolite was calculated as 196 mg/g, whereas the HA showed a higher Sr adsorption ratio than the zeolite. The maximum sorption capacity of Sr on the HA was 123 mg/g. Under coexistence with Fe, Cs adsorption on the zeolite decreased with increasing Fe concentration, reaching 2.0 ± 0.8% at 0.1 M Fe concentration. In contrast, Cs adsorption on the zeolite was improved by adding the HA. In the case of coexistence of the HA, the Cs adsorption on the mixture of the HA and the zeolite was 52.4% ± 3.6 % at 0.1 M Fe concentration, although Cs adsorption on the HA alone was quite low. In the Fe adsorption processes of the HA and the zeolite, the HA exhibited a maximum sorption capacity of 256 mg/g, which was much higher than that of the zeolite (111 mg/g). The high affinity of Fe on the HA contributes to the improvement of the deteriorated Cs adsorption on the zeolite due to Fe ions.

Selective Capture of Cesium and Thallium from Natural Waters and Simulated Wastes with Copper Ferrocyanide Functionalized Mesoporous Silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sangvanich, Thanapon; Sukwarotwat, Vichaya; Wiacek, Robert J.

2010-10-15

Copper(II) ferrocyanide immobilized inside mesoporous silica MCM-41 supports (Cu-FC-EDA-SAMMSTM) has been evaluated against iron(III) hexacyanoferrate(II) (insoluble Prussian blue) for the sorption of cesium (Cs+) and thallium (Tl+) from natural waters and simulated wastes. The affinities (in term of distribution coefficients, Kd) of both sorbents for Cs and Tl were measured as a function of solution pH, competing cations, and matrices. For the entire pH studied (pH 0.1 to 7.3), Cu-FC-EDA-SAMMS had higher affinities for Cs and Tl (one to two orders of magnitude higher Kd) than Prussian blue and was less negatively impacted by the solution pH, competing cations, andmore » matrices. The adsorption isotherms and kinetics of the two sorbents for Cs and/or Tl were also determined in seawater and simulated acid and alkaline wastes. SAMMS outperformed Prussian blue in terms of maximum adsorption capacity (e.g., 21.7 versus 2.6 mg Cs/g in acid waste stimulant, pH 1.1), and rate (e.g., over 95 wt% of Cs was removed after 2 minutes with SAMMS, while only 75 wt% was removed with Prussian blue). The lower affinity, capacity, and rate of Cs and Tl sorption on Prussian blue than those on Cu-FC-EDA-SAMMS were attributed to the molecular pore sizes, which restrict mass transport, and the insoluble Cs abducts of the Prussian blue, which restrict the ability of neighboring binding sites to further bind Cs ions. On the other hand, the large pores of SAMMS not only enable faster diffusion and faster binding chemistry, but they also allow isolation of binding sites so that one Cs binding event does not impact further Cs binding. In addition, iron (Fe) dissolved from insoluble Prussian blue over 10-fold of that from Cu-FC-EDA-SAMMS after 24 hours of contact time, indicating poorer material stability of Prussian blue.« less

Content of strontium-90 and cesium-137 in a number of regions of the Baltic Sea in 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarev, L.N.; Flegontov, V.M.; Gedenov, L.I.

1985-07-01

The authors present the data gathered from the samples of water and bed deposits taken at various sites in the Baltic Sea, the Gulf of Riga, and the Gulf of Finland. By means of the radiochemical method using ferrocyanide-carbonate concentration, they determine strotium-90 and cesium-137 content. The authors conclude by noting an increase in the cesium-137 content in the deep waters of the Baltic Sea and in bed deposits, and by cautioning that this development commands close attention.

A preliminary deposit model for lithium-cesium-tantalum (LCT) pegmatites

USGS Publications Warehouse

Bradley, Dwight; McCauley, Andrew

2013-01-01

This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. We emphasize practical aspects of pegmatite geology that might directly or indirectly help in exploration for lithium-cesium-tantalum (LCT) pegmatites, or for assessing regions for pegmatite-related mineral resource potential. These deposits are an important link in the world’s supply chain of rare and strategic elements, accounting for about one-third of world lithium production, most of the tantalum, and all of the cesium.

How can we make stable linear monoatomic chains? Gold-cesium binary subnanowires as an example of a charge-transfer-driven approach to alloying.

PubMed

Choi, Young Cheol; Lee, Han Myoung; Kim, Woo Youn; Kwon, S K; Nautiyal, Tashi; Cheng, Da-Yong; Vishwanathan, K; Kim, Kwang S

2007-02-16

On the basis of first-principles calculations of clusters and one dimensional infinitely long subnanowires of the binary systems, we find that alkali-noble metal alloy wires show better linearity and stability than either pure alkali metal or noble metal wires. The enhanced alternating charge buildup on atoms by charge transfer helps the atoms line up straight. The cesium doped gold wires showing significant charge transfer from cesium to gold can be stabilized as linear or circular monoatomic chains.

[Blastomogenic effect following single and chronic exposure to a mixture of cesium-137 and strontium-90].

PubMed

Danetskaia, E V; Lavrent'ev, L N; Zapol'skaia, N A

1976-01-01

The rate of tumor incidence in different rhythms of rat stomach exposure to cesium-137 and strontium-90 was analysed. The correlative values of the administered nucleids activity were selected by analogy with their content in global natural fall-out. In single exposure to the concentrations of 400 and 100 mc/per rat of cesium-137 and strontium-90 mixture accordingly, osteogenic osteosarcomas developed approximatley 4 times as frequently as in chronic administration of the same radionucleids in concentrations of 2 and 8 mc/per rat, correspondingly.

Cesium frequency standard for lasers at. Sigma. = 1. 06. mu. m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallmeroth, K.; Letterer, R.

1990-07-15

High-resolution spectra of the {ital X}{sup 1}{Sigma}{sup +}{sub {ital g}}--{ital A}{sup 1}{Sigma}{sup +}{sub {ital u}} band of molecular cesium at {lambda}=1.06 {mu}m have been measured. An absolute wave-number reference table for lasers emitting at {Sigma} = 1.06 {mu}m has been established. The cesium resonances are calibrated with respect to the well-known molecular-iodine absorption lines at {Sigma} = 0.53 {mu}m. An accuracy of 10{sup {minus}7} has been achieved.

Derivation of strontium-90 and cesium-137 residual radioactive material guidelines for the Laboratory for Energy-Related Health Research, University of California, Davis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nimmagadda, M.; Yu, C.

1993-04-01

Residual radioactive material guidelines for strontium-90 and cesium-137 were derived for the Laboratory for Energy-Related Health Research (LEHR) site in Davis, California. The guideline derivation was based on a dose limit of 100 mrem/yr. The US Department of Energy (DOE) residual radioactive material guideline computer code, RESRAD, was used in this evaluation; this code implements the methodology described in the DOE manual for implementing residual radioactive material guidelines. Three potential site utilization scenarios were considered with the assumption that, for a period of 1,000 years following remedial action, the site will be utilized without radiological restrictions. The defined scenarios varymore » with regard to use of the site, time spent at the site, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded within 1,000 years for either strontium-90 or cesium-137, provided that the soil concentrations of these radionuclides at the LEHR site do not exceed the following levels: 71,000 pCi/g for strontium-90 and 91 pCi/g for cesium-137 for Scenario A (researcher: the expected scenario); 160,000 pCi/g for strontium-90 and 220 pCi/g for cesium-137 for Scenario B (recreationist: a plausible scenario); and 37 pCi/g for strontium-90 and 32 pCi/g for cesium-137 for Scenario C (resident farmer ingesting food produced in the contaminated area: a plausible scenario). The derived guidelines are single-radionuclide guidelines and are linearly proportional to the dose limit used in the calculations. In setting the actual strontium-90 and cesium-137 guidelines for the LEHR site, DOE will apply the as low as reasonably achievable (ALARA) policy to the decision-making process, along with other factors such as whether a particular scenario is reasonable and appropriate.« less

Small Column Ion Exchange Testing of Superlig 644 for Removal of 137Cs from Hanford Tank Waste Envelope A (Tank 241-AW-101)

DOE Office of Scientific and Technical Information (OSTI.GOV)

DE Kurath; DL Blanchard; JR Bontha

The current BNFL Inc. flow sheet for the pretreatment of the Hanford High-Level tank wastes includes the use of Superlig{reg_sign} materials for the removal of {sup 137}Cs from the aqueous fraction of the waste. The Superlig materials applicable to cesium removal include the cesium selective Superlig 632 and Superlig 644. These materials have been developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. The work contained in this report involves testing the Superlig 644 ion exchange material in a small dual column system (15 mL each; L/D = 5.7). The sample processed was approximately 2.5 L of dilutedmore » waste [Na{sup +}] = 4.6M from Tank 241-AW-101 (Envelope A). This waste had been previously clarified in a single tube cross-flow filtration unit. All ion exchange process steps were tested including resin bed preparation, loading, feed displacement water rinse, elution and resin regeneration. During the initial run, the lag column did not perform as expected so that the {sup 137}Cs concentration in the effluent composite was above the LAW treatment limits. This required a second column run with the partially decontaminated feed that was conducted at a higher flow rate. A summary of performance measures for both runs is shown in Table S1. The Cs {lambda} values represent a measure of the effective capacity of the SL-644 resin. The Cs {lambda} of 143 for the lead column in run 1 is very similar to the value obtained by the Savannah River Technology Center during Phase 1A testing. The larger Cs {lambda} value for run 2 reflects a general trend for the effective capacity of the SL-644 material to increase as the cesium concentration decreases. The low value for the lag column during the first run indicates that it did not perform as expected. This may have been due to insufficient conditioning of the bed prior to the start of the loading step or to air in the bed that caused channeling. Equilibrium data obtained with batch contacts using the AW-101 Cs IX feed indicates a range for the Cs {lambda} of 80--97. The maximum decontamination factor (DF) for {sup 137}CS is based on analysis of the first samples collected from each column and the concentration in the feed for each run. While the DF's are lower for the second run, this is attributed to the lower {sup 137}Cs concentration in the feed and the increased flowrate. The overall composite DF for run 2 was quite good since both columns functioned well. The overall DF for both runs was 3,000, which provided an effluent with a {sup 137}Cs concentration of 5.89E-02 Ci/m{sup 3} (C/C{sub 0} = 3.3 IE-04). The {sup 137}Cs concentration in the effluent composite was 7.3% of the contract limit for {sup 137}Cs and also below the basis of design limit.« less

Environmental application of cesium-137 irradiation technology: Sludges and foods

NASA Astrophysics Data System (ADS)

Sivinski, Jacek S.

Several activities have been undertaken to investigate and implement the use of the military byproduct cesium-137 in ways which benefit mankind. Gamma radiation from cesium-137 has been shown to be effective in reducing pathogens in sewage sludge to levels where reuse of the material in public areas meets current regulatory criteria for protection of public health. Food irradiation at doses of 10 kGy or less have been found by international expert committees to be wholesome and safe for human consumption. Cesium-137 can be used as a means of enhancing particular properties of various food commodities by means of sterilization, insect disinfestation, delayed senescence and ripening, and sprout inhibition. This paper discusses the U.S. Department of Energy Beneficial Uses Program research and engineering history, as well as current activities and future plans, relating to both sewage sludge and food irradiation.

Cesium and Strontium Retentions Governed by Aluminosilicate Gel in Alkali-Activated Cements

PubMed Central

Jang, Jeong Gook; Park, Sol Moi; Lee, Haeng Ki

2017-01-01

The present study investigates the retention mechanisms of cesium and strontium for alkali-activated cements. Retention mechanisms such as adsorption and precipitation were examined in light of chemical interactions. Batch adsorption experiments and multi-technical characterizations by using X-ray diffraction, zeta potential measurements, and the N2 gas adsorption/desorption methods were conducted for this purpose. Strontium was found to crystalize in alkali-activated cements, while no cesium-bearing crystalline phases were detected. The adsorption kinetics of alkali-activated cements having relatively high adsorption capacities were compatible with pseudo-second-order kinetic model, thereby suggesting that it is governed by complex multistep adsorption. The results provide new insight, demonstrating that characteristics of aluminosilicate gel with a highly negatively charged surface and high micropore surface area facilitated more effective immobilization of cesium and strontium in comparison with calcium silicate hydrates. PMID:28772803

Cesium injection system for negative ion duoplasmatrons

DOEpatents

Kobayashi, Maasaki; Prelec, Krsto; Sluyters, Theodorus J

1978-01-01

Longitudinally extending, foraminous cartridge means having a cylindrical side wall forming one flat, circular, tip end surface and an opposite end; an open-ended cavity, and uniformly spaced orifices for venting the cavity through the side wall in the annulus of a plasma ring for uniformly ejecting cesium for coating the flat, circular, surface. To this end, the cavity is filled with a cesium containing substance and attached to a heater in a hollow-discharge duoplasmatron. By coating the flat circular surface with a uniform monolayer of cesium and locating it in an electrical potential well at the end of a hollow-discharge, ion duoplasmatron source of an annular hydrogen plasma ring, the negative hydrogen production from the duoplasmatron is increased. The negative hydrogen is produced on the flat surface of the cartridge and extracted by the electrical potential well along a trajectory coaxial with the axis of the plasma ring.

[Radioactive cesium analysis in radiation-tainted beef by gamma-ray spectrometry with germanium semiconductor detector].

PubMed

Minatani, Tomiaki; Nagai, Hiroyuki; Nakamura, Masashi; Otsuka, Kimihito; Sakai, Yoshimichi

2012-01-01

The detection limit and precision of radioactive cesium measurement in beef by gamma-ray spectrometry with a germanium semiconductor detector were evaluated. Measurement for 2,000 seconds using a U-8 container (100 mL) provided a detection limit of radioactive cesium (the sum of 134Cs and 137Cs) of around 20 Bq/kg. The 99% confidence interval of the measurement of provisional maximum residue limit level (491 Bq/kg) samples ranged from 447 to 535 Bq/kg. Beef is heterogeneous, containing muscle and complex fat layers. Depending on the sampled parts, the measurement value is variable. It was found that radioactive cesium content of the muscle layer was clearly different from that of fat, and slight differences were observed among parts of the sample (SD=16.9 Bq/kg), even though the same region (neck block) of beef sample was analyzed.

Assessment of self-help methods to reduce potential exposure to radiological contamination after a large-scale radiological release.

PubMed

Snyder, Emily; Drake, John; Cardarelli, John; Hall, Kathy; Szabo, Jeff; Demmer, Rick; Lindberg, Michael; Riggs, Karen; James, Ryan

2014-09-01

After the release of radioactive materials from a large radiological dispersal device (e.g., dirty bomb), improvised nuclear detonation, or nuclear power plant accident, up to hundreds of square miles may be contaminated. A portion of this area will be evacuated; however, people living in the portion that is not evacuated yet is still contaminated with low-levels of radioactive contamination will be asking for ways they can reduce their exposure. Whether cleaning activities can significantly reduce exposure is not fully understood. In this effort, the ability of cleaning activities to remove cesium (137Cs) was studied. The removal efficacy of cleaning with a commercial product, Simple Green®, was compared to cleaning with water for hard surfaces typically seen in residences. The removal efficacy of laundering fabric material surfaces was also determined for a range of conditions (e.g., fabric material type, wash temperature). During these studies, assessments of the implications of these activities (e.g., cross-contamination, resulting waste streams) were also completed. Simple Green and water were effective for removing 137Cs from plastic laminate and vinyl flooring (93.4-96.8%) but were not effective for removing 137Cs from painted wallboard and wood (7.3-68.1%). It was also determined that there was no significant difference between the two cleaners on all of the surfaces, except plastic laminate, for which Simple Green was slightly more effective. Laundering was effective for removing 137Cs contamination from polyester and cotton swatches and cotton comforters (up to 96.8% in the single swatch testing).

Thermionic energy converter investigations

NASA Technical Reports Server (NTRS)

Goodale, D. B.; Lee, C.; Lieb, D.; Oettinger, P. E.

1979-01-01

This paper presents evaluation of a variety of thermionic converter configurations to obtain improved efficiency. A variable-spacing diode using an iridium emitter gave emission properties comparable to platinum, but the power output from a sintered LaB6 collector diode was not consistent with its work function. Reflectivities above 0.5 were measured at thermal energies on oxygenated-cesiated surfaces using a field emission retarding potential gun. Performance of converters with structured electrodes and the characteristics of a pulsed triode were studied as a function of emitter, collector, cesium reservoir, interelectrode spacing, xenon pressure, and pulsing parameters.

Bismuth Based Hybrid Perovskites A3Bi2 I9 (A: Methylammonium or Cesium) for Solar Cell Application.

PubMed

Park, Byung-Wook; Philippe, Bertrand; Zhang, Xiaoliang; Rensmo, Håkan; Boschloo, Gerrit; Johansson, Erik M J

2015-11-18

Low-toxic bismuth-based perovskites are prepared for the possible replacement of lead perovskite in solar cells. The perovskites have a hexagonal crystalline phase and light absorption in the visible region. A power conversion efficiency of over 1% is obtained for a solar cell with Cs3 Bi2 I9 perovskite, and it is concluded that bismuth perovskites have very promising properties for further development in solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-podant diglycolamides and room temperature ionic liquid impregnated resins: An excellent combination for extraction chromatography of actinides.

PubMed

Gujar, R B; Ansari, S A; Verboom, W; Mohapatra, P K

2016-05-27

Extraction chromatography resins, prepared by impregnating two multi-podant diglycolamide ligands, viz. diglycolamide-functionalized calix[4]arene (C4DGA) and tripodal diglycolamide (T-DGA) dissolved in the room temperature ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (RTIL: C4mimTf2N) on Chromosorb-W (an inert solid support), gave excellent results for the removal of trivalent actinides from acidic waste solutions. Distribution coefficient measurements on several metal ions showed selective sorption of Am(III) over hexavalent uranyl ions and other fission product elements such as strontium and cesium. The sorbed metal ions could be efficiently desorbed with a complexing solution containing guanidine carbonate and EDTA buffer. The sorption of Am(III) on both resins followed pseudo-second order rate kinetics with rate constants of 1.37×10(-6) and 6.88×10(-7)g/cpmmin for T-DGA and C4DGA resins, respectively. The metal sorption on both resins indicated the Langmuir monolayer chemisorption phenomenon with Eu(III) sorption capacities of 4.83±0.21 and 0.52±0.05mg per g of T-DGA and C4DGA resins, respectively. The results of column studies show that these resins are of interest for a possible application for the recovery of hazardous trivalent actinides from dilute aqueous solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

A Cesium fountain frequency standard: Preliminary results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clairon, A.; Laurent, P.; Santarelli, G.

1994-12-31

Laser cooling of atoms has opened up new possibilities in the field of atomic frequency standards. A Cesium atomic fountain, first proposed by Zacharias in 1953, is now feasible: the atoms, first cooled by six laser beams, are launched upward using laser light, pass once through a microwave cavity, continue their ballistic flight and then fall through the same cavity. The long time between the two microwave interactions leads to a Ramsey resonance much narrower than in conventional Cs clocks using thermal atomic beams. The stability and accuracy of such a cesium fountain am very attractive. The use of diodemore » lasers to cool, launch and detect cesium atoms in a low cesium pressure cell allows the construction of a simple and reliable atomic fountain frequency standard. A fountain frequency standard is now in operation at LPTF. A Ramsey resonance as narrow as 0.8 Hz has been obtained. A few days of continuous operation are routinely obtained. In closed loop operation the fountain frequency standard is continuously monitored against a H maser allowing an evaluation of the accuracy of the device. The present short- term frequency stability is about 5.10{sup -13} {tau}{sup -1/2} limited only by the frequency noise of the microwave source. We intend to present a preliminary evaluation of this new standard with a discussion of the major systematic effects which determine the accuracy. The expected accuracy will be at 10-14 level. In addition, we will present a description of the whole design of the cesium fountain.« less

Quantitative determination of cesium binding to ferric hexacyanoferrate: Prussian blue.

PubMed

Faustino, Patrick J; Yang, Yongsheng; Progar, Joseph J; Brownell, Charles R; Sadrieh, Nakissa; May, Joan C; Leutzinger, Eldon; Place, David A; Duffy, Eric P; Houn, Florence; Loewke, Sally A; Mecozzi, Vincent J; Ellison, Christopher D; Khan, Mansoor A; Hussain, Ajaz S; Lyon, Robbe C

2008-05-12

Ferric hexacyanoferrate (Fe4III[FeII(CN)6]3), also known as insoluble Prussian blue (PB) is the active pharmaceutical ingredient (API) of the drug product, Radiogardase. Radiogardase is the first FDA approved medical countermeasure for the treatment of internal contamination with radioactive cesium (Cs) or thallium in the event of a major radiological incident such as a "dirty bomb". A number of pre-clinical and clinical studies have evaluated the use of PB as an investigational decorporation agent to enhance the excretion of metal cations. There are few sources of published in vitro data that detail the binding capacity of cesium to insoluble PB under various chemical and physical conditions. The study objective was to determine the in vitro binding capacity of PB APIs and drug products by evaluating certain chemical and physical factors such as medium pH, particle size, and storage conditions (temperature). In vitro experimental conditions ranged from pH 1 to 9, to cover the range of pH levels that PB may encounter in the gastrointestinal (GI) tract in humans. Measurements of cesium binding were made between 1 and 24h, to cover gastric and intestinal tract residence time using a validated atomic emission spectroscopy (AES) method. The results indicated that pH, exposure time, storage temperature (affecting moisture content) and particle size play significant roles in the cesium binding to both the PB API and the drug product. The lowest cesium binding was observed at gastric pH of 1 and 2, whereas the highest cesium binding was observed at physiological pH of 7.5. It was observed that dry storage conditions resulted in a loss of moisture from PB, which had a significant negative effect on the PB cesium binding capacity at time intervals consistent with gastric residence. Differences were also observed in the binding capacity of PB with different particle sizes. Significant batch to batch differences were also observed in the binding capacity of some PB API and drug products. Our results suggest that certain physiochemical properties affect the initial binding capacity and the overall binding capacity of PB APIs and drug products during conditions that simulated gastric and GI residence time. These physiochemical properties can be utilized as quality attributes to monitor and predict drug product quality under certain manufacturing and storage conditions and may be utilized to enhance the clinical efficacy of PB.

Cesium lead halide perovskite quantum dot-based warm white light-emitting diodes with high color rendering index

NASA Astrophysics Data System (ADS)

Bi, Ke; Wang, Dan; Wang, Peng; Duan, Bin; Zhang, Tieqiang; Wang, Yinghui; Zhang, Hanzhuang; Zhang, Yu

2017-05-01

White light-emitting diodes (WLEDs) were fabricated by employing a combination of a commercial yellow emission Ce3+-doped Y3Al5O12 (YAG:Ce)-based phosphor and all-inorganic perovskite quantum dots pumped with blue LED chip. Perovskite quantum dot solution was used as the color conversion layer with liquid-type structure. Red-emitting materials based on cesium lead halide (CsPb(X)3) perovskite quantum dots were introduced to generate WLEDs with high efficacy and high color rendering index through compensating the red emission of the YAG:Ce phosphor-based commercialized WLEDs. The experimental results suggested that the luminous efficiency and color rendering index of the as-prepared WLED device could reach up to 84.7 lm/W and 89, respectively. The characteristics of those devices including correlated color temperature (CCT), color rendering index (CRI), and color coordinates were observed under different forward currents. The as-fabricated warm WLEDs showed excellent color stability against the increasing current, while the color coordinates shifted slightly from (0.3837, 0.3635) at 20 mA to (0.3772, 0.3592) at 120 mA and color temperature tuned from 3803 to 3953 K.

Magnetic Nanofluid Rare Earth Element Extraction Process Report, Techno Economic Analysis, and Results for Geothermal Fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pete McGrail

This GDR submission is an interim technical report and raw data files from the first year of testing on functionalized nanoparticles for rare earth element extraction from geothermal fluids. The report contains Rare Earth Element uptake results (percent removal, mg Rare Earth Element/gram of sorbent, distribution coefficient) for the elements of Neodymium, Europium, Yttrium, Dysprosium, and Cesium. A detailed techno economic analysis is also presented in the report for a scaled up geothermal rare earth element extraction process. All rare earth element uptake testing was done on simulated geothermal brines with one rare earth element in each brine. The raremore » earth element uptake testing was conducted at room temperature.« less

Technology Evaluation Report: Non-destructive ...

EPA Pesticide Factsheets

Technology Evaluation Report HSRP is working to develop tools and information that will help detect the intentional introduction of chemical or biological contaminants in buildings or water systems, the containment of these contaminants, the decontamination of buildings and/or water systems, and the management of wastes generated from decontamination and cleanup operations. Evaluation of the performance of CBI Polymers’ DeconGelTM 1108, Environmental Alternatives, Inc.’s (EAI’s) Rad-Release II (RRII), Environmental Alternatives, Inc.’s SuperGel, and Intek Technologies’ LH-21. The objective of evaluating these technologies was to test their ability to remove radioactive cesium (Cs)-137 from the mixed building material coupons of brick with mortar, tile with grout, granite with mortar, all mortar and all grout coupons.

Small Column Ion Exchange Design and Safety Strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huff, T.; Rios-Armstrong, M.; Edwards, R.

2011-02-07

Small Column Ion Exchange (SCIX) is a transformational technology originally developed by the Department of Energy (DOE) Environmental Management (EM-30) office and is now being deployed at the Savannah River Site (SRS) to significantly increase overall salt processing capacity and accelerate the Liquid Waste System life-cycle. The process combines strontium and actinide removal using Monosodium Titanate (MST), Rotary Microfiltration, and cesium removal using Crystalline Silicotitanate (CST, specifically UOP IONSIV{reg_sign}IE-911 ion exchanger) to create a low level waste stream to be disposed in grout and a high level waste stream to be vitrified. The process also includes preparation of the streamsmore » for disposal, e.g., grinding of the loaded CST material. These waste processing components are technically mature and flowsheet integration studies are being performed including glass formulations studies, application specific thermal modeling, and mixing studies. The deployment program includes design and fabrication of the Rotary Microfilter (RMF) assembly, ion-exchange columns (IXCs), and grinder module, utilizing an integrated system safety design approach. The design concept is to install the process inside an existing waste tank, Tank 41H. The process consists of a feed pump with a set of four RMFs, two IXCs, a media grinder, three Submersible Mixer Pumps (SMPs), and all supporting infrastructure including media receipt and preparation facilities. The design addresses MST mixing to achieve the required strontium and actinide removal and to prevent future retrieval problems. CST achieves very high cesium loadings (up to 1,100 curies per gallon (Ci/gal) bed volume). The design addresses the hazards associated with this material including heat management (in column and in-tank), as detailed in the thermal modeling. The CST must be size reduced for compatibility with downstream processes. The design addresses material transport into and out of the grinder and includes provisions for equipment maintenance including remote handling. The design includes a robust set of nuclear safety controls compliant with DOE Standard (STD)-1189, Integration of Safety into the Design Process. The controls cover explosions, spills, boiling, aerosolization, and criticality. Natural Phenomena Hazards (NPH) including seismic event, tornado/high wind, and wildland fire are considered. In addition, the SCIX process equipment was evaluated for impact to existing facility safety equipment including the waste tank itself. SCIX is an innovative program which leverages DOE's technology development capabilities to provide a basis for a successful field deployment.« less

Influence of the Dirac-Hartree-Fock starting potential on the parity-nonconserving electric-dipole-transition amplitudes in cesium and thallium

NASA Technical Reports Server (NTRS)

Perger, W. F.; Das, B. P.

1987-01-01

The parity-nonconserving electric-dipole-transition amplitudes for the 6s1/2-7s1/2 transition in cesium and the 6p1/2-7p1/2 transition in thallium have been calculated by the Dirac-Hartree-Fock method. The effects of using different Dirac-Hartree-Fock atomic core potentials are examined and the transition amplitudes for both the length and velocity gauges are given. It is found that the parity-nonconserving transition amplitudes exhibit a greater dependence on the starting potential for thallium than for cesium.

Using Cesium for 3D Thematic Visualisations on the Web

NASA Astrophysics Data System (ADS)

Gede, Mátyás

2018-05-01

Cesium (http://cesiumjs.org) is an open source, WebGL-based JavaScript library for virtual globes and 3D maps. It is an excellent tool for 3D thematic visualisations, but to use its full functionality it has to be feed with its own file format, CZML. Unfortunately, this format is not yet supported by any major GIS software. This paper intro- duces a plugin for QGIS, developed by the author, which facilitates the creation of CZML file for various types of visualisations. The usability of Cesium is also examined in various hardware/software environments.

INVESTIGATIONS ON THE BIOLOGICAL BEHAVIOR OF RADIOACTIVE FISSION PRODUCTS IN PREGNANT ANIMALS. III. ENRICHMENT OF RADIOCESIUM IN NURSING RATS AND THE MODIFICATION OF THE Cs RETENTION IN ORGANS OF THE MOTHER DURING THE LACTATION PERIOD (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriegel, H.; Weber, E.

In a continuation of the investigation on the placental turnover of radiocesium in the rat, the changes of the postpartum cesium content in the young nursing animals caused by the amounts of cesium, which are excreted with the mother-milk, are described. The cesium content in the organs of the mother at the end of the lactation period is decreased by 50% in contrast to the un- pregnant controls. (auth)

The biological impacts of ingested radioactive materials on the pale grass blue butterfly

NASA Astrophysics Data System (ADS)

Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Tanahara, Akira; Otaki, Joji M.

2014-05-01

A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area.

Weather from 250 Miles Up: Visualizing Precipitation Satellite Data (and Other Weather Applications) Using CesiumJS

NASA Technical Reports Server (NTRS)

Lammers, Matt

2017-01-01

Geospatial weather visualization remains predominately a two-dimensional endeavor. Even popular advanced tools like the Nullschool Earth display 2-dimensional fields on a 3-dimensional globe. Yet much of the observational data and model output contains detailed three-dimensional fields. In 2014, NASA and JAXA (Japanese Space Agency) launched the Global Precipitation Measurement (GPM) satellite. Its two instruments, the Dual-frequency Precipitation Radar (DPR) and GPM Microwave Imager (GMI) observe much of the Earth's atmosphere between 65 degrees North Latitude and 65 degrees South Latitude. As part of the analysis and visualization tools developed by the Precipitation Processing System (PPS) Group at NASA Goddard, a series of CesiumJS [Using Cesium Markup Language (CZML), JavaScript (JS) and JavaScript Object Notation (JSON)] -based globe viewers have been developed to improve data acquisition decision making and to enhance scientific investigation of the satellite data. Other demos have also been built to illustrate the capabilities of CesiumJS in presenting atmospheric data, including model forecasts of hurricanes, observed surface radar data, and gridded analyses of global precipitation. This talk will present these websites and the various workflows used to convert binary satellite and model data into a form easily integrated with CesiumJS.

The biological impacts of ingested radioactive materials on the pale grass blue butterfly.

PubMed

Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Tanahara, Akira; Otaki, Joji M

2014-05-15

A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area.

Cesium-diode performances from the 1963-to-1971 Thermionic Conversion Specialist Conferences

NASA Technical Reports Server (NTRS)

Morris, J. F.

1972-01-01

Indexes and summaries of the conference papers containing cesium-diode results are presented. Lists of converter materials, geometries, conditions, outputs, and lifetimes accompany the references. Simple chemical designations for emitters, collectors, and additives direct the reader to appropriate selections.

Study on the Volatility of Cesium in Dry Ashing Pretreatment and Dissolution of Ash by Microwave Digestion System - 13331

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Kwang-Soon; Lee, Chang Heon; Ahn, Hong-Joo

2013-07-01

Based on the regulation of the activity concentration of Cs-137, Co-58, Co-60, Fe-55, Ni-59, Ni-63, Sr-90, Nb-94, and Tc-99, and the total alpha from the radioactive waste acceptance criteria, the measurement of the activity concentration of these nuclides in low and intermediate levels of radioactive waste such as in paper, cotton, vinyl and plastic samples was investigated. A dry ashing method was applied to obtain a concentration effect of the samples. Owing to the temperature dependence of the volatility for cesium, the temperature of 300 to 650 deg. C was examined. It was found that 450 deg. C is themore » optimum dry ashing temperature. After dry ashing, the produced ash was dissolved with HNO{sub 3}, HCl, and HF by a high-performance microwave digestion system. The ash sample, for the most part, was completely dissolved with 10 mL of HNO{sub 3}, 4 mL of HCl, and 0.25 mL of HF by a high-performance microwave digestion system using a nova high temperature rotor at 250 deg. C for 90 min until reaching 0.2 g. To confirm the reliability of cesium loss after the performance of the dry ashing procedure, a cesium standard solution for AAS and a Cs-137 standard solution for gamma spectrometry were added to a paper towel or a planchet of stainless steel, respectively. Cesium was measured by AAS, ICP-MS, and gamma spectrometry. The volatility of cesium did not occur until 450 deg. C ashing. (authors)« less

Web-Based Geospatial Visualization of GPM Data with CesiumJS

NASA Technical Reports Server (NTRS)

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.

[Optimization and comparison of nitrogen and phosphorus removal by different aeration modes in oxidation ditch].

PubMed

Guo, Chang-Zi; Peng, Dang-Cong; Cheng, Xue-Mei; Wang, Dan

2012-03-01

The oxidation ditch operation mode was simulated by sequencing batch reactor (SBR) system with alternate stirring and aeration. The nitrogen and phosphorus removal efficiencies were investigated in two different aeration modes: point aeration and step aeration. Experimental results show that oxygen is dissolved more efficiently in point aeration mode with a longer aerobic region in the same air supply capacity, but dissolved oxygen (DO) utilization efficiency for nitrogen and phosphorus removal is high in step aeration mode. Nitrification abilities of the two modes are equal with ammonia-nitrogen (NH4(+) -N) removal efficiency of 96.68% and 97.03%, respectively. Nitrifier activities are 4.65 and 4.66 mg x (g x h)(-1) respectively. When the ratio of anoxic zones and the aerobic zones were 1, the total nitrogen (TN) removal efficiency of point aeration mode in 2, 4 or 7 partitions was respectively 60.14%, 47.93% and 33.7%. The total phosphorus (TP) removal efficiency was respectively 28.96%, 23.75% and 24.31%. The less the partitions, the higher the nitrogen and phosphorus removal efficiencies, but it is in more favor of TN removal. As for step aeration mode with only one partitioning zone, the TN and TP removal efficiencies are respectively 64.21% and 49.09%, which is better than in point aeration mode, but more conducive to the improvement of TP removal efficiency. Under the condition of sufficient nitrification in step aeration mode, the nitrogen and phosphorus removal is better with the increase of anoxic zone. The removal efficiencies of TN and TP respectively rose to 73.94% and 54.18% when the ratio of anoxic zones and the aerobic zones was increased from 1 : 1 to 1. 8 : 1. As the proportion of anoxic zones was enlarged further, nitrification and operation stability were weakened so as to affect the nitrogen and phosphorus removal efficiencies.

INTERACTIONS BETWEEN CESIUM AND DISPERSED KAOLINITE POWDERS AT HIGH TEMPERATURES FOR TREATMENT OF MIXED WASTES

EPA Science Inventory

Kaolinite sorbents were found to manage emissions of vapor phase cesium, when the kaolinite was injected into the combustor, having maximum value between 1400 and 1500 K. The mechanism of this process and its quantification await further research.

HIGH TEMPERATURE SORPTION OF CESIUM AND STRONTIUM ON DISPERSED KAOLINITE POWDERS

EPA Science Inventory

Sorption of cesium and strontium on kaolinite powders was investigated as a means to minimize the emissions of these metals during certain high-temperature processes currently being developed to isolate and dispose of radiological and mixed wastes. In this work, nonradioactive aq...

Nano-scale investigations of electric-dipole-layer enhanced field and thermionic emission from high current density cathodes

NASA Astrophysics Data System (ADS)

Vlahos, Vasilios

Cesium iodide coated graphitic fibers and scandate cathodes are two important electron emission technologies. The coated fibers are utilized as field emitters for high power microwave sources. The scandate cathodes are promising thermionic cathode materials for pulsed power vacuum electron devices. This work attempts to understand the fundamental physical and chemical relationships between the atomic structure of the emitting cathode surfaces and the superior emission characteristics of these cathodes. Ab initio computational modeling in conjunction with experimental investigations was performed on coated fiber cathodes to understand the origin of their very low turn on electric field, which can be reduced by as much as ten-fold compared to uncoated fibers. Copious amounts of cesium and oxygen were found co-localized on the fiber, but no iodine was detected on the surface. Additional ab initio studies confirmed that cesium oxide dimers could lower the work function significantly. Surface cesium oxide dipoles are therefore proposed as the source of the observed reduction in the turn on electric field. It is also proposed that emission may be further enhanced by secondary electrons from cesium oxide during operation. Thermal conditioning of the coated cathode may be a mechanism by which surface cesium iodide is converted into cesium oxide, promoting the depletion of iodine by formation of volatile gas. Ab initio modeling was also utilized to investigate the stability and work functions of scandate structures. The work demonstrated that monolayer barium-scandium-oxygen surface structures on tungsten can dramatically lower the work function of the underlying tungsten substrate from 4.6 eV down to 1.16 eV, by the formation of multiple surface dipoles. On the basis of this work, we conclude that high temperature kinetics force conventional dispenser cathodes (barium-oxygen monolayers on tungsten) to operate in a non-equilibrium compositional steady state with higher than optimal work functions of ˜2 eV. We hypothesize that scandium enables the barium-oxygen surface monolayer kinetics to access a more thermodynamically stable phase with reported work functions as low as ˜1.3 eV.

40 CFR 63.9323 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.9323 Section 63.9323 Protection of Environment... determine the add-on control device emission destruction or removal efficiency? You must use the procedures... removal efficiency as part of the performance test required by § 63.9310. You must conduct three test runs...

40 CFR 63.9323 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.9323 Section 63.9323 Protection of Environment... determine the add-on control device emission destruction or removal efficiency? You must use the procedures... removal efficiency as part of the performance test required by § 63.9310. You must conduct three test runs...

40 CFR 63.4166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4166 Section 63.4166 Protection of Environment....4166 How do I determine the add-on control device emission destruction or removal efficiency? (a) For... device organic emissions destruction or removal efficiency, using Equation 2 of this section. ER23JY02...

40 CFR 63.3966 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.3966 Section 63.3966 Protection of Environment... or removal efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test...

40 CFR 63.4965 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4965 Section 63.4965 Protection of Environment....4965 How do I determine the add-on control device emission destruction or removal efficiency? You must... destruction or removal efficiency as part of the performance test required by § 63.4960. You must conduct...

40 CFR 63.3966 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.3966 Section 63.3966 Protection of Environment... or removal efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test...

Space Agriculture for Recovery of Fukushima from the Nuclear Disaster

NASA Astrophysics Data System (ADS)

Yamashita, Masamichi; Tomita-Yokotani, Kaori; Hasegawa, Katsuya; Kanazawa, Shinjiro; Oshima, Tairo

2012-07-01

Space agriculture is an engineering challenge to realize life support functions on distant planetary bodies under their harsh environment. After the nuclear disaster in Fukushima, its land was heavily contaminated by radioactive cesium and other nuclei. We proposed the use of space agriculture to remediate the contaminated land. Since materials circulation in the human dominant system should remove sodium from metabolic waste at processing fertilizer for crop plants, handling of sodium and potassium ions in agro-ecosystem has been one of major research targets of space agriculture. Cesium resembles to potassium as alkaline metal. Knowledge on behavior of sodium/potassium in agro-ecosystem might contribute to Fukushima. Reduction of volume of contaminated biomass made by hyperthermophilic aerobic composting bacterial system is another proposal from space agriculture. Volume and mass of plant bodies should be reduced for safe storage of nuclear wastes. Capacity of the storage facility will be definitely limited against huge amount of contaminated soil, plants and others. For this purpose, incineration of biomass first choice. The process should be under the lowered combustion temperature and with filters to confine radioactive ash to prevent dispersion of radioactive cesium. Biological combustion made by hyperthermophilic aerobic composting bacterial system might offer safe alternative for the volume reduction of plant biomass. Scientific evidence are demanded for Fukushima in order to to judge health risks of the low dose rate exposure and their biological mechanism. Biology and medicine for low dose rate exposure have been intensively studied for space exploration. The criteria of radiation exposure for general public should be remained as 1 mSv/year, because people has no merit at being exposed. However, the criteria of 1,200 mSv for life long, which is set to male astronaut, age of his first flight after age 40, might be informative to people for understanding the less risk of low dose rate against the acute exposure of same total dose. Scientific achievements of space radiobiology and medicine help people to assess their risk of exposure to radiation and to find effective measures against it. Knowledge for quantitative comparison of risks need to be provided. Space agriculture is a promising testbed to solve the Fukushima problems.

Biosorption of cesium-137 and strontium-90 by mucilaginous seeds of Ocimum basilicum.

PubMed

Chakraborty, Dipjyoti; Maji, Samir; Bandyopadhyay, Abhijit; Basu, Sukalyan

2007-11-01

Mucilaginous seeds of Ocimum basilicum were used in uptake studies with cesium-137 and strontium-90. Results showed that uptake was dependent on the structural integrity of the mucilage fibrils. Water imbibed seeds showed higher adsorption of both 137Cs and 90Sr in comparison to seeds pretreated with NaOH, HCl and Na-periodate solution. The uptake was pH dependent and while some divalent metal ions had no or little detrimental effect, the alkali metal ions Li+, Na+ and K+ decreased the uptake. The maximum adsorption capacity was 160 mg cesium g(-1) and 247 mg strontium g(-1) seed dry weight.

Performance of preproduction model cesium beam frequency standards for spacecraft applications

NASA Technical Reports Server (NTRS)

Levine, M. W.

1978-01-01

A cesium beam frequency standards for spaceflight application on Navigation Development Satellites was designed and fabricated and preliminary testing was completed. The cesium standard evolved from an earlier prototype model launched aboard NTS-2 and the engineering development model to be launched aboard NTS satellites during 1979. A number of design innovations, including a hybrid analog/digital integrator and the replacement of analog filters and phase detectors by clocked digital sampling techniques are discussed. Thermal and thermal-vacuum testing was concluded and test data are presented. Stability data for 10 to 10,000 seconds averaging interval, measured under laboratory conditions, are shown.

Collisional Dynamics of the Cesium D1 and D2 Transitions

DTIC Science & Technology

2010-09-01

37 14. Comparison of Phase Changing Probability and Polarizability ...Phase Changing Probability and Polarizability for D2 Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 25...theoretically determined the values for broadening and shift rates for cesium with Argon , Krypton, and Xenon from the interatomic potentials [27]. The rates

Highly crystallized nanometer-sized zeolite a with large Cs adsorption capability for the decontamination of water.

PubMed

Torad, Nagy L; Naito, Masanobu; Tatami, Junichi; Endo, Akira; Leo, Sin-Yen; Ishihara, Shinsuke; Wu, Kevin C-W; Wakihara, Toru; Yamauchi, Yusuke

2014-03-01

Nanometer-sized zeolite A with a large cesium (Cs) uptake capability is prepared through a simple post-milling recrystallization method. This method is suitable for producing nanometer-sized zeolite in large scale, as additional organic compounds are not needed to control zeolite nucleation and crystal growth. Herein, we perform a quartz crystal microbalance (QCM) study to evaluate the uptake ability of Cs ions by zeolite, to the best of our knowledge, for the first time. In comparison to micrometer-sized zeolite A, nanometer-sized zeolite A can rapidly accommodate a larger amount of Cs ions into the zeolite crystal structure, owing to its high external surface area. Nanometer-sized zeolite is a promising candidate for the removal of radioactive Cs ions from polluted water. Our QCM study on Cs adsorption uptake behavior provides the information of adsorption kinetics (e.g., adsorption amounts and rates). This technique is applicable to other zeolites, which will be highly valuable for further consideration of radioactive Cs removal in the future. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rational Synthesis of Hollow Prussian Blue Analogue Through Coordination Replication and Controlled-Etching for Cs-Ion Removal.

PubMed

Xu, Jun; Bu, Fan-Xing; Guo, Yi-Fei; Zhang, Wei; Hu, Ming; Jiang, Ji-Sen

2018-05-01

Radioactive cesium pollution have received considerable attention due to the increasing risks in development of the nuclear power plants in the world. Although various functional porous materials are utilized to adsorb Cs+ ions in water, Prussian blue analogues (PBAs) are an impressive class of candidates because of their super affinity of Cs+ ions. The adsorption ability of the PBAs strongly relate to the mesostructure and interstitial sites. To design a hollow PBA with large number of interstitial sites, the traditional hollowing methods are not suitable owing to the difficulty in processing the specific PBAs with large number of interstitial sites. In this work, we empolyed a rational strategy which was to form a "metal oxide"@"PBA" core-shell structure via coordination replication at first, then utilized a mild etching to remove the metal oxide core, led to hollow PBA finally. The obtained hollow PBAs were of high crystallinity and large number of interstitial sites, showing a super adsorption performance for Cs+ ions (221.6 mg/g) within a short period (10 min).

40 CFR 63.3166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.3166 Section 63.3166 Protection of Environment... Limitations § 63.3166 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.3160. You must...

40 CFR 63.3166 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.3166 Section 63.3166 Protection of Environment... Limitations § 63.3166 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.3160. You must...

40 CFR 63.4766 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4766 Section 63.4766 Protection of Environment... Option § 63.4766 How do I determine the add-on control device emission destruction or removal efficiency... emission destruction or removal efficiency as part of the performance test required by § 63.4760. You must...

Virus removal efficiency of Cambodian ceramic pot water purifiers.

PubMed

Salsali, Hamidreza; McBean, Edward; Brunsting, Joseph

2011-06-01

Virus removal efficiency is described for three types of silver-impregnated, ceramic water filters (CWFs) produced in Cambodia. The tests were completed using freshly scrubbed filters and de-ionized (DI) water as an evaluation of the removal efficiency of the virus in isolation with no other interacting water quality variables. Removal efficiencies between 0.21 and 0.45 log are evidenced, which is significantly lower than results obtained in testing of similar filters by other investigators utilizing surface or rain water and a less frequent cleaning regime. Other experiments generally found virus removal efficiencies greater than 1.0 log. This difference may be because of the association of viruses with suspended solids, and subsequent removal of these solids during filtration. Variability in virus removal efficiencies between pots of the same manufacturer, and observed flow rates outside the manufacturer's specifications, suggest tighter quality control and consistency may be needed during production.

Application of Zero-Valent Iron Nanoparticles for the Removal of Aqueous Zinc Ions under Various Experimental Conditions

PubMed Central

Liang, Wen; Dai, Chaomeng; Zhou, Xuefei; Zhang, Yalei

2014-01-01

Application of zero-valent iron nanoparticles (nZVI) for Zn2+ removal and its mechanism were discussed. It demonstrated that the uptake of Zn2+ by nZVI was efficient. With the solids concentration of 1 g/L nZVI, more than 85% of Zn2+ could be removed within 2 h. The pH value and dissolved oxygen (DO) were the important factors of Zn2+ removal by nZVI. The DO enhanced the removal efficiency of Zn2+. Under the oxygen-contained condition, oxygen corrosion gave the nZVI surface a shell of iron (oxy)hydroxide, which could show high adsorption affinity. The removal efficiency of Zn2+ increased with the increasing of the pH. Acidic condition reduced the removal efficiency of Zn2+ by nZVI because the existing H+ inhibited the formation of iron (oxy)hydroxide. Adsorption and co-precipitation were the most likely mechanism of Zn2+ removal by nZVI. The FeOOH-shell could enhance the adsorption efficiency of nZVI. The removal efficiency and selectivity of nZVI particles for Zn2+ were higher than Cd2+. Furthermore, a continuous flow reactor for engineering application of nZVI was designed and exhibited high removal efficiency for Zn2+. PMID:24416439

The Effect of Alkaline Earth Metal on the Cesium Loading of Ionsiv(R) IE-910 and IE-911

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fondeur, F.F.

2001-01-16

This study investigated the effect of variances in alkaline earth metal concentrations on cesium loading of IONSIV(R) IE-911. The study focused on Savannah River Site (SRS) ''average'' solution with varying amounts of calcium, barium and magnesium.

CESIUM RECOVERY FROM AQUEOUS SOLUTIONS

DOEpatents

Goodall, C.A.

1960-09-13

A process is given for precipitating cesium on zinc ferricyanide (at least 0.0004 M) from aqueous solutions containing mineral acid in a concentration of from 0.2 N acidity to 0.61 N acid-deficiency and advantageously, but not necessarily, also aluminum nitrate in a concentration of from l to 2.5 M.

Thermionic energy conversion technology - Present and future

NASA Technical Reports Server (NTRS)

Shimada, K.; Morris, J. F.

1977-01-01

Aerospace and terrestrial applications of thermionic direct energy conversion and advances in direct energy conversion (DEC) technology are surveyed. Electrode materials, the cesium plasma drop (the difference between the barrier index and the collector work function), DEC voltage/current characteristics, conversion efficiency, and operating temperatures are discussed. Attention is centered on nuclear reactor system thermionic DEC devices, for in-core or out-of-core operation. Thermionic fuel elements, the radiation shield, power conditions, and a waste heat rejection system are considered among the thermionic DEC system components. Terrestrial applications include topping power systems in fossil fuel and solar power generation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamliton, T F

Rongelap Atoll experienced close-in or local fallout from the U.S. nuclear test program conducted in the northern Marshall Islands between 1946 and 1958. By all internationally agreed scientific criteria, Rongelap Island is considered safe for permanent resettlement. However, the amount of bomb-related radioactivity in soil and vegetation is, on average, about 5 times greater in the northern islands of the atoll because the centerline of the fallout pattern from the 1954 thermonuclear ''Bravo'' test extended over this part of the atoll. The most important radioactive element remaining on the atoll is radioactive cesium (cesium-137). Cesium-137 emits what is called amore » ''gamma ray'' that can penetrate the body and deliver both an external (outside the body) and internal (from inside the body) gamma dose to inhabitants of Rongelap Atoll. Cesium-137 is taken up from the soil into locally grown foodstuffs such as coconut, Pandanus and breadfruit. Significant quantities of cesium-137 may also be found in coconut crab. The internal dose delivered to people eating these products will be directly proportional to the concentration of cesium-137 in the food and the amount consumed. The external gamma dose will depend on the concentration of cesium-137 in the soil and the amount of time spent in the area. The highest concentration of cesium-137 in surface soils of the northern islands of Rongelap Atoll is about equivalent to that measured on Bikini Island. Under the radiation protection criteria adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal, permanent resettlement of these islands would require intervention because of the higher radiation doses that could potentially be delivered to inhabitants living on a diet derived largely from local foods. A more realistic lifestyle scenario is that the resettled population on Rongelap Island will occasionally visit the northern part of the atoll for food gathering, fishing and other recreational activities. It is estimated that a person spending 8 hours (1 work day) in the interior of the Rongelap Atoll northern islands will receive a maximum additional external dose of around 0.1-0.2 mrem per day. Furthermore, Lawrence Livermore National Laboratory's environmental monitoring continues to show that the marine environment contains very low levels of bomb radioactivity. Similarly, the occasional consumption of terrestrial foods including coconut crab from the northern islands is not expected to add significantly to the radiological health risk of living on Rongelap Island. The average annual effective ingestion dose for Rongelap Island resettlement in 2002 is estimated to be around 1-2 mrem per year when imported foods are made available and proposed remediation efforts take effect. This estimate is about twice that of the Rongelap Island resettlement worker population using direct measurements from the whole body counting program. Resettlement workers presently living on the islands receive an average internal dose from cesium-137 of less than 1 mrem (0.01 mSv) per year. These workers are known to eat locally grown foods and coconut crabs collected from the northern islands. The highest individual dose observed was 4 mrem (0.04 mSv) per year. Under the guidelines adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal, it is concluded that diving, fishing and visiting any northern island of Rongelap Atoll are safe activities for limited periods. Eating local fish and other marine life such as clams would also be considered safe. Consumption of plant foods from the northern islands of Rongelap Atoll depends on successful implementation of specific remediation measures to ensure dietary intakes of cesium-137 remain at or below levels considered safe. The whole body counting program should continue to monitor the actual internal levels of cesium-137 among people eating plants and coconut crabs gathered from the northern islands of Rongelap Atoll islands until such time that the Nuclear Claims Tribunal guidelines are met.« less

Statistical estimate of mercury removal efficiencies for air pollution control devices of municipal solid waste incinerators.

PubMed

Takahashi, Fumitake; Kida, Akiko; Shimaoka, Takayuki

2010-10-15

Although representative removal efficiencies of gaseous mercury for air pollution control devices (APCDs) are important to prepare more reliable atmospheric emission inventories of mercury, they have been still uncertain because they depend sensitively on many factors like the type of APCDs, gas temperature, and mercury speciation. In this study, representative removal efficiencies of gaseous mercury for several types of APCDs of municipal solid waste incineration (MSWI) were offered using a statistical method. 534 data of mercury removal efficiencies for APCDs used in MSWI were collected. APCDs were categorized as fixed-bed absorber (FA), wet scrubber (WS), electrostatic precipitator (ESP), and fabric filter (FF), and their hybrid systems. Data series of all APCD types had Gaussian log-normality. The average removal efficiency with a 95% confidence interval for each APCD was estimated. The FA, WS, and FF with carbon and/or dry sorbent injection systems had 75% to 82% average removal efficiencies. On the other hand, the ESP with/without dry sorbent injection had lower removal efficiencies of up to 22%. The type of dry sorbent injection in the FF system, dry or semi-dry, did not make more than 1% difference to the removal efficiency. The injection of activated carbon and carbon-containing fly ash in the FF system made less than 3% difference. Estimation errors of removal efficiency were especially high for the ESP. The national average of removal efficiency of APCDs in Japanese MSWI plants was estimated on the basis of incineration capacity. Owing to the replacement of old APCDs for dioxin control, the national average removal efficiency increased from 34.5% in 1991 to 92.5% in 2003. This resulted in an additional reduction of about 0.86Mg emission in 2003. Further study using the methodology in this study to other important emission sources like coal-fired power plants will contribute to better emission inventories. Copyright © 2010 Elsevier B.V. All rights reserved.

Microwave-to-optical frequency conversion with a Rydberg atom coupled to a coplanar waveguide

NASA Astrophysics Data System (ADS)

Gard, Bryan; Jacobs, Kurt; McDermott, Robert; Saffman, Mark

2017-04-01

A primary candidate for converting quantum information from microwave to optical frequencies is the use of Rydberg states of a single atom trapped near a surface. The fact that the Rydberg states possess both large electric dipole moments and microwave transition frequencies allows them to interact with superconducting mesoscopic circuits. By considering a concrete example, that of a Cesium atom, and using numerical search methods to optimize the control protocols, we determine the fidelities and transmission rates that could be achievable with such a device. We show that while protocols that exploit the adiabatic STIRAP mechanism provide the best raw transfer fidelities, the fastest communication speeds can be obtained by using heralding, which allows one to remove the adiabatic constraint. Support from Oak Ridge Associated Universities.

Operational frequency stability of rubidium and cesium frequency standards

NASA Technical Reports Server (NTRS)

Lavery, J. E.

1973-01-01

The frequency stabilities under operational conditions of several commercially available rubidium and cesium frequency standards were determined from experimental data for frequency averaging times from 10 to the 7th power s and are presented in table and graph form. For frequency averaging times between 10 to the 5th power and 10 to the 7th power s, the rubidium standards tested have a stability of between 10 to the minus 12th power and 5 x 10 to the minus 12th power, while the cesium standards have a stability of between 2 x 10 to the minus 13th power and 5 x 10 to the minus 13th power.

Cesium titanium silicate and method of making

DOEpatents

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.

Cesium titanium silicate and method of making

DOEpatents

Balmer, M.L.

1997-01-07

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. 10 figs.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology

NASA Astrophysics Data System (ADS)

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium.

Cesium 137-Its applications for understanding soil redistribution and deposition patterns on the landscape

USDA-ARS?s Scientific Manuscript database

In the 1960s research began on the application of fallout radionuclides to determine sediment deposition and soil redistribution rates and patterns in agricultural and natural ecosystems. This research was based on the use of fallout 137Cesium (137Cs) from nuclear weapon tests deposited worldwide d...

Laser-cooled cesium fountain clock: design and expected performances

NASA Astrophysics Data System (ADS)

Clairon, Andre; Laurent, Phillipe; Nadir, A.; Santarelli, G.; Drewsen, M.; Grison, D.; Lounis, B.; Salomon, C.

1993-04-01

The use of diode lasers to cool and trap Cesium atoms in a low Cs pressure cell allows the construction of a relatively simple and reliable atomic fountain frequency standard. Here we discuss the design and the potentialities of the Cs clock frequency standards being built at L.P.T.F..

Cesium Eluate Physical Property Determination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baich, M.A.

2001-02-13

Two bench-scale process simulations of the proposed cesium eluate evaporation process of concentrating eluate produced in the Hanford Site Waste Treatment Plant were conducted. The primary objective of these experiments was to determine the physical properties and the saturation concentration of the eluate evaporator bottoms while producing condensate approximately 0.50 molar HN03.

Nuclear breeder reactor fuel element with axial tandem stacking and getter

DOEpatents

Gibby, Ronald L.; Lawrence, Leo A.; Woodley, Robert E.; Wilson, Charles N.; Weber, Edward T.; Johnson, Carl E.

1981-01-01

A breeder reactor fuel element having a tandem arrangement of fissile and fertile fuel with a getter for fission product cesium disposed between the fissile and fertile sections. The getter is effective at reactor operating temperatures to isolate the cesium generated by the fissile material from reacting with the fertile fuel section.

Fission product release from fuel under LWR accident conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osborne, M.F.; Lorenz, R.A.; Norwood, K.S.

Three tests have provided additional data on fission product release under LWR accident conditions in a temperature range (1400 to 2000/sup 0/C). In the release rate data are compared with curves from a recent NRC-sponsored review of available fission product release data. Although the iodine release in test HI-3 was inexplicably low, the other data points for Kr, I, and Cs fall reasonably close to the corresponding curve, thereby tending to verify the NRC review. The limited data for antimony and silver release fall below the curves. Results of spark source mass spectrometric analyses were in agreement with the gammamore » spectrometric results. Nonradioactive fission products such as Rb and Br appeared to behave like their chemical analogs Cs and I. Results suggest that Te, Ag, Sn, and Sb are released from the fuel in elemental form. Analysis of the cesium and iodine profiles in the thermal gradient tube indicates that iodine was deposited as CsT along with some other less volatile cesium compound. The cesium profiles and chemical reactivity indicate the presence of more than one cesium species.« less

Cesium isotope ratios as indicators of nuclear power plant operations.

PubMed

Delmore, James E; Snyder, Darin C; Tranter, Troy; Mann, Nick R

2011-11-01

There are multiple paths by which radioactive cesium can reach the effluent from reactor operations. The radioactive (135)Cs/(137)Cs ratios are controlled by these paths. In an effort to better understand the origin of this radiation, these (135)Cs/(137)Cs ratios in effluents from three power reactor sites have been measured in offsite samples. These ratios are different from global fallout by up to six fold and as such cannot have a significant component from this source. A cesium ratio for a sample collected outside of the plant boundary provides integration over the operating life of the reactor. A sample collected inside the plant at any given time can be much different from this lifetime ratio. The measured cesium ratios vary significantly for the three reactors and indicate that the multiple paths have widely varying levels of contributions. There are too many ways these isotopes can fractionate to be useful for quantitative evaluations of operating parameters in an offsite sample, although it may be possible to obtain limited qualitative information for an onsite sample. Copyright © 2011 Elsevier Ltd. All rights reserved.

The cesiator - A device for cesium vapor control and impurity purge

NASA Astrophysics Data System (ADS)

Rasor, N. S.; Desplat, J.-L.

A new type of liquid cesium reservoir that maintains a temperature-independent cesium pressure, continuously recirculates cesium vapor through the TFE (thermionic fuel element), and purges it of impurities is discussed. This device, the cesiator, is based on well-established gas-buffered heat pipe principles. The cesiator offers new TFE design options for fission product/impurity handling that eliminate the need for an intercell insulator seal and associated failure modes. Cesiator performance requirements are estimated based on data for expected release of fission products and their effect on TFE performance. The effect of design parameters on cesiator performance is described. Experimentation with an ethanol-metal mock-up revealed an unexpected but desirable mode of operation that autoregulates the pressure drop and flow of vapor in the external circuit and that has been incorporated in the reference design for phase II development. Experimental techniques for measuring the local temperature, pressure, and composition in a condensing vapor were successfully developed. A reference design for a TFE cesiator was defined for prototype design, development, and test.

Optimal thermionic energy conversion with established electrodes for high-temperature topping and process heating. [coal combustion product environments

NASA Technical Reports Server (NTRS)

Morris, J. F.

1980-01-01

Applied research-and-technology (ART) work reveals that optimal thermionic energy conversion (TEC) with approximately 1000 K to approximately 1100 K collectors is possible using well established tungsten electrodes. Such TEC with 1800 K emitters could approach 26.6% efficiency at 27.4 W/sq cm with approximately 1000 K collectors and 21.7% at 22.6 W/sq cm with approximately 1100 K collectors. These performances require 1.5 and 1.7 eV collector work functions (not the 1 eV ultimate) with nearly negligible interelectrode losses. Such collectors correspond to tungsten electrode systems in approximately 0.9 to approximately 6 torr cesium pressures with 1600 K to 1900 K emitters. Because higher heat-rejection temperatures for TEC allow greater collector work functions, interelectrode loss reduction becomes an increasingly important target for applications aimed at elevated temperatures. Studies of intragap modifications and new electrodes that will allow better electron emission and collection with lower cesium pressures are among the TEC-ART approaches to reduced interelectrode losses. These solutions will provide very effective TEC to serve directly in coal-combustion products for high-temperature topping and process heating. In turn this will help to use coal and to use it well.

Exciton-to-Dopant Energy Transfer in Mn-Doped Cesium Lead Halide Perovskite Nanocrystals.

PubMed

Parobek, David; Roman, Benjamin J; Dong, Yitong; Jin, Ho; Lee, Elbert; Sheldon, Matthew; Son, Dong Hee

2016-12-14

We report the one-pot synthesis of colloidal Mn-doped cesium lead halide (CsPbX 3 ) perovskite nanocrystals and efficient intraparticle energy transfer between the exciton and dopant ions resulting in intense sensitized Mn luminescence. Mn-doped CsPbCl 3 and CsPb(Cl/Br) 3 nanocrystals maintained the same lattice structure and crystallinity as their undoped counterparts with nearly identical lattice parameters at ∼0.2% doping concentrations and no signature of phase separation. The strong sensitized luminescence from d-d transition of Mn 2+ ions upon band-edge excitation of the CsPbX 3 host is indicative of sufficiently strong exchange coupling between the charge carriers of the host and dopant d electrons mediating the energy transfer, essential for obtaining unique properties of magnetically doped quantum dots. Highly homogeneous spectral characteristics of Mn luminescence from an ensemble of Mn-doped CsPbX 3 nanocrystals and well-defined electron paramagnetic resonance spectra of Mn 2+ in host CsPbX 3 nanocrystal lattices suggest relatively uniform doping sites, likely from substitutional doping at Pb 2+ . These observations indicate that CsPbX 3 nanocrystals, possessing many superior optical and electronic characteristics, can be utilized as a new platform for magnetically doped quantum dots expanding the range of optical, electronic, and magnetic functionality.

Carbollide solubility and chemical compatibility summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCabe, D.J.

1993-08-17

This report examines the value of the cobalt dicarbollide anion as an effective form of in-tank precipitation. The cobalt dicarbollide anion (CDC) has been investigated for the possible replacement of tetraphenyl borate anion (TPB) for precipitation of cesium in SRS High Level Waste (HLW). The solubility of the cesium CDC in 5 M salt solutions and the reactivity with caustic have been studied extensively. The solubility of CSCDC in a mixture of 4 M sodium nitrate and 1 m sodium hydroxide is {approximately}2 {times} 10{sup {minus}3} M at 40{degrees}C. Furthermore, the CDC decomposes in 1 M sodium hydroxide solution withmore » apparent first order kinetics with a half-life of 7.3 days at 60 {degrees}C and 94 days at 40{degrees}C. Tank temperatures are currently estimated to approach 60{degrees}C during the ITP filtration cycle. This solubility and rapid decomposition of the CDC under highly alkaline conditions and high temperature would require increasing the quantity of CDC and nonradioactive cesium which must be added, increasing the cost of production. Increasing the quantity of CDC would necessitate recovery of the material, probably using a solvent extraction system. Due to the large amount of nonradioactive cesium which must be added, the total amount of precipitate formed exceeds that for TPB precipitation. Also, formation of sodium and/or potassium precipitates compete with cesium salt precipitation in 5 M salt solutions at lower temperature (<30{degrees}C). Decomposition generates hydrogen, which may lead to process complications.« less

eWaterCycle visualisation. combining the strength of NetCDF and Web Map Service: ncWMS

NASA Astrophysics Data System (ADS)

Hut, R.; van Meersbergen, M.; Drost, N.; Van De Giesen, N.

2016-12-01

As a result of the eWatercycle global hydrological forecast we have created Cesium-ncWMS, a web application based on ncWMS and Cesium. ncWMS is a server side application capable of reading any NetCDF file written using the Climate and Forecasting (CF) conventions, and making the data available as a Web Map Service(WMS). ncWMS automatically determines available variables in a file, and creates maps colored according to map data and a user selected color scale. Cesium is a Javascript 3D virtual Globe library. It uses WebGL for rendering, which makes it very fast, and it is capable of displaying a wide variety of data types such as vectors, 3D models, and 2D maps. The forecast results are automatically uploaded to our web server running ncWMS. In turn, the web application can be used to change the settings for color maps and displayed data. The server uses the settings provided by the web application, together with the data in NetCDF to provide WMS image tiles, time series data and legend graphics to the Cesium-NcWMS web application. The user can simultaneously zoom in to the very high resolution forecast results anywhere on the world, and get time series data for any point on the globe. The Cesium-ncWMS visualisation combines a global overview with local relevant information in any browser. See the visualisation live at forecast.ewatercycle.org

Time-resolved production and detection of reactive atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grossman, L. W.; Hurst, G. S.

1977-09-01

Cesium iodide in the presence of a buffer gas was dissociated with a pulsed ultraviolet laser, which will be referred to as the source laser. This created a population of atoms at a well defined time and in a compact, well defined volume. A second pulsed laser, with a beam that completely surrounded that of the first, photoionized the cesium after a known time delay. This laser will be referred to as the detector laser. It was determined that for short time delays, all of the cesium atoms were easily ionized. When focused, the source laser generated an extremely intensemore » fluence. By accounting for the beam intensity profile it was shown that all of the molecules in the central portion of the beam can be dissociated and detected. Besides proving the feasibility of single-molecule detection, this enabled a determination of the absolute photodissociation cross section as a function of wavelength. Initial studies of the time decay of the cesium signal at low argon pressures indicated a non-exponential decay. This was consistent with a diffusion mechanism transporting cesium atoms out of the laser beam. Therefore, it was desired to conduct further experiments using a tightly focused source beam, passing along the axis of the detector beam. The theoretical behavior of this simple geometry accounting for diffusion and reaction is easily calculated. A diffusion coefficient can then be extracted by data fitting. If reactive decay is due to impurities constituting a fixed percentage of the buffer gas, then two-body reaction rates will scale linearly with pressure and three-body reaction rates will scale quadratically. Also, the diffusion coefficient will scale inversely with pressure. At low pressures it is conceivable that decay due to diffusion would be sufficiently rapid that all other processes can be neglected. Extraction of a diffusion coefficient would then be quite direct. Finally, study of the reaction of cesium and oxygen was undertaken.« less

Integrating a High Resolution Optically Pumped Magnetometer with a Multi-Rotor UAV towards 3-D Magnetic Gradiometry

NASA Astrophysics Data System (ADS)

Braun, A.; Walter, C. A.; Parvar, K.

2016-12-01

The current platforms for collecting magnetic data include dense coverage, but low resolution traditional airborne surveys, and high resolution, but low coverage terrestrial surveys. Both platforms leave a critical observation gap between the ground surface and approximately 100m above ground elevation, which can be navigated efficiently by new technologies, such as Unmanned Aerial Vehicles (UAVs). Specifically, multi rotor UAV platforms provide the ability to sense the magnetic field in a full 3-D tensor, which increases the quality of data collected over other current platform types. Payload requirements and target requirements must be balanced to fully exploit the 3-D magnetic tensor. This study outlines the integration of a GEM Systems Cesium Vapour UAV Magnetometer, a Lightware SF-11 Laser Altimeter and a uBlox EVK-7P GPS module with a DJI s900 Multi Rotor UAV. The Cesium Magnetometer is suspended beneath the UAV platform by a cable of varying length. A set of surveys was carried out to optimize the sensor orientation, sensor cable length beneath the UAV and data collection methods of the GEM Systems Cesium Vapour UAV Magnetometer when mounted on the DJI s900. The target for these surveys is a 12 inch steam pipeline located approximately 2 feet below the ground surface. A systematic variation of cable length, sensor orientation and inclination was conducted. The data collected from the UAV magnetometer was compared to a terrestrial survey conducted with the GEM GST-19 Proton Procession Magnetometer at the same elevation, which also served a reference station. This allowed for a cross examination between the UAV system and a proven industry standard for magnetic field data collection. The surveys resulted in optimizing the above parameters based on minimizing instrument error and ensuring reliable data acquisition. The results demonstrate that optimizing the UAV magnetometer survey can yield to industry standard measurements.

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

PubMed

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

2014-04-22

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. (137)Cs is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is therefore of considerable importance. The extraction was facilitated by the ligand octyl(phenyl)-N,N'-diisobutylcarbamoylphosphine oxide (CMPO) used in TRans-Uranium EXtraction processes and investigated through well established liquid|liquid electrochemistry. This study gave access to the metal ion to ligand (1:n) stoichiometry and overall complexation constant, β, of the interfacial complexation reaction which were determined to be 1:3 and 1.6×10(11) at the w|P66614TB interface while the study at w|o elicited an n equal to 1 with β equal to 86.5. Through a straightforward relationship, these complexation constant values were converted to distribution coefficients, δ(α), with the ligand concentrations studied for comparison to other studies present in the literature; the w|o and w|IL systems gave δ(α) of 2 and 8.2×10(7), respectively, indicating a higher overall extraction efficiency for the latter. For the w|o system, the metal ion-ligand stoichiometries were confirmed through isotopic distribution analysis of mass spectra obtained by the direct injection of an emulsified water-organic solvent mixture into an electron spray ionization mass spectrometer. Copyright © 2014 Elsevier B.V. All rights reserved.

Space Electric Research Test in the Electric Propulsion Laboratory

NASA Image and Video Library

1964-06-21

Technicians prepare the Space Electric Research Test (SERT-I) payload for a test in Tank Number 5 of the Electric Propulsion Laboratory at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Lewis researchers had been studying different methods of electric rocket propulsion since the mid-1950s. Harold Kaufman created the first successful engine, the electron bombardment ion engine, in the early 1960s. These electric engines created and accelerated small particles of propellant material to high exhaust velocities. Electric engines have a very small amount of thrust, but once lofted into orbit by workhorse chemical rockets, they are capable of small, continuous thrust for periods up to several years. The electron bombardment thruster operated at a 90-percent efficiency during testing in the Electric Propulsion Laboratory. The package was rapidly rotated in a vacuum to simulate its behavior in space. The SERT-I mission, launched from Wallops Island, Virginia, was the first flight test of Kaufman’s ion engine. SERT-I had one cesium engine and one mercury engine. The suborbital flight was only 50 minutes in duration but proved that the ion engine could operate in space. The Electric Propulsion Laboratory included two large space simulation chambers, one of which is seen here. Each uses twenty 2.6-foot diameter diffusion pumps, blowers, and roughing pumps to remove the air inside the tank to create the thin atmosphere. A helium refrigeration system simulates the cold temperatures of space.

The promotional effects of cesium promoter on higher alcohol synthesis from syngas over cesium-promoted Cu/ZnO/Al2O3 catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Jie; Cai, Qiuxia; Wan, Yan

In this study, the promotional effects of cesium promoter on higher alcohol (C2+OH) synthesis from syngas over Cs-Cu/ZnO/Al2O3 catalysts were investigated using a combined experimental and theoretical density functional theory (DFT) calculation method. In the presence of cesium, the C2+OH productivity increases from 77.1 g•kgcat-1•h-1 to 157.3 g•kgcat-1•h-1 at 583 K due to the enhancement of the initial C–C bond formation. Detailed analysis of chain growth probabilities (CGPs) confirms that initial C–C bond formation is the rate-determining step in the temperature range of 543-583 K. Addition of cesium promoter significantly increases the productivities of 2-methyl-1-propanol, while the CGPs values (C3*more » to 2-methyl-C3*) is almost unaffected. With the assistance of cesium promoter, the CGPs of the initial C–C bond formation step (C1* to C2*) could be increased from 0.13 to 0.25 at 583 K. DFT calculations indicate that the initial C–C bond formation is mainly contributed by the HCO+HCO coupling reaction over the ZnCu(211) model surface. In the presence of the Cs2O, the stabilities of key reaction intermediates such as HCO and H2CO are enhanced which facilitates both HCO+HCO and HCO+H2CO coupling reaction steps with lower activation barriers over the Cs2O-ZnCu(211) surface. The promotional effects of cesium on the C2+OH productivity are also benefited from the competitive CH+HCO coupling reaction over CH hydrogenation that leads to lower alkane formation. In addition, Bader charge analysis suggests that the presence of cesium ions would facilitate the nucleophilic reaction between HCO and H2CO for initial C–C bond formation. This work was supported by the National Natural Science Foundation of China (No. 91545114 and No. 91545203). We appreciate the joint PhD scholarship support from the China Scholarship Council. The authors would also like to thank the support from Collaborative Innovation Center of Chemistry for Energy Materials (2011-iChEM). DM was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences. Computing time was granted by the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). EMSL is a national scientific user facility located at Pacific Northwest National Laboratory (PNNL) and sponsored by DOE’s Office of Biological and Environmental Research. PNNL is a multiprogram national laboratory operated for DOE by Battelle Memorial Institute. We also appreciate the support from Sinochem Quanzhou Petrochemical Co. Ltd.« less

The TELEC - A plasma type of direct energy converter. [Thermo-Electronic Laser Energy Converter for electric power generation

NASA Technical Reports Server (NTRS)

Britt, E. J.

1978-01-01

The Thermo-Electronic Laser Energy Converter (TELEC) is a high-power density plasma device designed to convert a 10.6-micron CO2 laser beam into electric power. Electromagnetic radiation is absorbed in plasma electrons, creating a high-electron temperature. Energetic electrons diffuse from the plasma and strike two electrodes having different areas. The larger electrode collects more electrons and there is a net transport of current. An electromagnetic field is generated in the external circuit. A computer program has been designed to analyze TELEC performance allowing parametric variation for optimization. Values are presented for TELEC performance as a function of cesium pressure and for current density and efficiency as a function of output voltage. Efficiency is shown to increase with pressure, reaching a maximum over 45%.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology.

PubMed

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium. Copyright © 2017 Elsevier B.V. All rights reserved.

Adsorption of SO2 and NO from incineration flue gas onto activated carbon fibers.

PubMed

Liu, Zhen-Shu

2008-11-01

Activated carbon fibers (ACFs) were used to remove SO2 and NO from incineration flue gas. Three types of ACFs in their origin state and after pretreatment with HNO3, NaOH, and KOH were investigated. The removal efficiencies of SO2 and NO were determined experimentally at defined SO2 and NO concentrations and at temperatures of 150, 200 and 260 degrees C. Experimental results indicated that the removal efficiencies of SO2 and NO using the original ACFs were < 56% and < 27%, respectively. All ACFs modified with HNO3, NaOH, and KOH solution could increase the removal efficiencies of SO(2) and NO. The mesopore volumes and functional groups of ACFs are important in determining the removal of SO2 and NO. When the mesopore volumes of the ACFs are insufficient for removing SO2 and NO, the functional groups on the ACFs are not important in determining the removal of SO2 and NO. On the contrary, the effects of the functional groups on the removal of SO2 and NO are more important than the mesopore volumes as the amount of mesopores on the ACFs is sufficient to remove SO2 and NO. Moreover, the removal efficiencies of SO2 and NO were greatest at 200 degrees C. When the inlet concentration of SO2 increased to 600 ppm, the removal efficiency of SO2 increased slightly and the removal efficiency of NO decreased.

Removal of Cu2+ and turbidity from wastewater by mercaptoacetyl chitosan.

PubMed

Chang, Qing; Zhang, Min; Wang, Jinxi

2009-09-30

A macromolecule heavy metal flocculant mercaptoacetyl chitosan (MAC) was prepared by reacting chitosan with mercaptoacetic acid. In preliminary experiments, the flocculation performance of MAC was evaluated by using wastewater containing Cu(2+) or/and turbidity. Some factors which affect the removal of Cu(2+) and turbidity were also studied. The experimental results showed that: (1) MAC can remove both Cu(2+) and turbidity from wastewater. The removal efficiency of Cu(2+) by using MAC combined with hydrolyzed polyacrylamide is higher than that by only using MAC, the removal efficiency of Cu(2+) reaches above 98%; (2) when water sample containing not only Cu(2+) but also turbidity-causing substance, the removal efficiency of both Cu(2+) and turbidity will be promoted by the cooperation effect of each other, the residual concentration of Cu(2+) reaches below 0.5 mg L(-1) and the turbidity reaches below 3NTU, Cu(2+) is more easily removed by MAC when turbidity is higher; (3) the removal efficiency of Cu(2+) increases with the increase in pH value, contrarily removal efficiency of turbidity decreases with the increase in pH value.

Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?

PubMed

Kocatürk-Schumacher, Nazlı Pelin; Zwart, Kor; Bruun, Sander; Brussaard, Lijbert; Jensen, Lars Stoumann

2017-05-01

Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium, orthophosphate and dissolved organic carbon (DOC) from the liquid fraction of digestate. Our objectives were to investigate the effect of the initial loading ratio between liquid and biochar on nutrient removal, and to investigate the effect of combining biochar with clinoptilolite on nutrient and DOC removal efficiency. Increasing the initial loading ratios increased nutrient concentrations on biochar to 8.61 mg NH 4 -N g -1 , 1.95 mg PO 4 -P g -1 and 13.01 mg DOC g -1 , but resulted in decreasing removal efficiencies. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and DOC removal efficiencies compared to biochar alone, but did not significantly change PO 4 -P removal efficiencies. Removal efficiencies with combined sorbents were up to 67% for ammonium, 58% for DOC and 58% for potassium. Clinoptilolite showed higher removal efficiencies compared to biochar alone, and combining clinoptilolite with biochar improved only total P removal efficiency. Concentrating nutrients with clinoptilolite and biochar may be an option when both sorbents are available at low cost.

Cesium-137 Fallout in Indiana Soil

ERIC Educational Resources Information Center

Whitman, Richard T.

2017-01-01

Atomic weapons testing during the Cold War and accidents at nuclear power plants have resulted in the release of radioactive fallout over great distances. Little is known about levels of fallout deposited in Indiana. The reported study sampled soil in all 92 Indiana counties to determine the present level of cesium-137 from the 2 to 12 centimeter…

Physical property measurements of doped cesium iodide crystals

NASA Technical Reports Server (NTRS)

Synder, R. S.; Clotfelter, W. N.

1974-01-01

Mechanical and thermal property values are reported for crystalline cesium iodide doped with sodium and thallium. Young's modulus, bulk modulus, shear modulus, and Poisson's ratio were obtained from ultrasonic measurements. Young's modulus and the samples' elastic and plastic behavior were also measured under tension and compression. Thermal expansion and thermal conductivity were the temperature dependent measurements that were made.

Ultralow-power local laser control of the dimer density in alkali-metal vapors through photodesorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jha, Pankaj K.; Scully, Marlan O.; Princeton University, Princeton, New Jersey 08544

2012-08-27

Ultralow-power diode-laser radiation is employed to induce photodesorption of cesium from a partially transparent thin-film cesium adsorbate on a solid surface. Using resonant Raman spectroscopy, we demonstrate that this photodesorption process enables an accurate local optical control of the density of dimer molecules in alkali-metal vapors.

Cesium recovery from aqueous solutions

DOEpatents

Goodhall, C. A.

1960-09-13

A process for recovering cesium from aqueous solutions is given in which precipitation on zinc ferricyanide is used. The precipitation is preferably carried out in solutions containing at least 0.0004M zinc ferricyanide, an acidity ranging from 0.2N mineral acid to 0.61N acid deficiency, and 1 to 2.5M aluminum nitrate. (D.L.C.)

Process for making a cesiated diamond film field emitter and field emitter formed therefrom

DOEpatents

Anderson, D.F.; Kwan, S.W.

1999-03-30

A process for making a cesiated diamond film comprises (a) depositing a quantity of cesium iodide on the diamond film in a vacuum of between about 10{sup {minus}4} Torr and about 10{sup {minus}7} Torr, (b) increasing the vacuum to at least about 10{sup {minus}8} Torr, and (c) imposing an electron beam upon the diamond film, said electron beam having an energy sufficient to dissociate said cesium iodide and to incorporate cesium into interstices of the diamond film. The cesiated diamond film prepared according to the process has an operating voltage that is reduced by a factor of at least approximately 2.5 relative to conventional, non-cesiated diamond film field emitters. 2 figs.

Process for making a cesiated diamond film field emitter and field emitter formed therefrom

DOEpatents

Anderson, David F.; Kwan, Simon W.

1999-01-01

A process for making a cesiated diamond film comprises (a) depositing a quantity of cesium iodide on the diamond film in a vacuum of between about 10.sup.-4 Torr and about 10.sup.-7 Torr, (b) increasing the vacuum to at least about 10.sup.-8 Torr, and (c) imposing an electron beam upon the diamond film, said electron beam having an energy sufficient to dissociate said cesium iodide and to incorporate cesium into interstices of the diamond film. The cesiated diamond film prepared according to the process has an operating voltage that is reduced by a factor of at least approximately 2.5 relative to conventional, non-cesiated diamond film field emitters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakravarti, D.; Held, E.E.

Radiocesium and stable potassium levels were determined in samples of muscle tissue of Birgus latro, the coconut crab, collected at Rongelap Atoll, Marshall Islands, during March and August 1958 and March 1959, and at Utirik Atoll in March 1959. Levels of cesium-137 ranged betwoen 731 d/m/g dry weight at Kabelle Island, Rongelap Atoll, and 28 d/m/g dry weight at Utirik Island, Utirik Atoll. The average potassium value for all samples was 13.05 mg/g dry weight with a standard deviation of 3.66. No significant correlation between cesium-l37 and potassium levels was found. There wse no significant difference in the average levelsmore » of cesium-137 in crabs collected at different times at the same island. (auth)« less

Precision mass measurements of cesium isotopes—new entries in the ISOLTRAP chronicles

NASA Astrophysics Data System (ADS)

Atanasov, D.; Beck, D.; Blaum, K.; Borgmann, Ch; Cakirli, R. B.; Eronen, T.; George, S.; Herfurth, F.; Herlert, A.; Kowalska, M.; Kreim, S.; Litvinov, Yu A.; Lunney, D.; Manea, V.; Neidherr, D.; Rosenbusch, M.; Schweikhard, L.; Wienholtz, F.; Wolf, R. N.; Zuber, K.

2017-04-01

Alkali ion beams are among the most intense produced by the ISOLDE facility. These were the first to be studied by the ISOLTRAP mass spectrometer and ever since, new measurements have been regularly reported. Recently the masses of very neutron-rich and short-lived cesium isotopes were determined at ISOLTRAP. The isotope 148Cs was measured directly for the first time by Penning-trap mass spectrometry. Using the new results, the trend of two-neutron separation energies in the cesium isotopic chain is revealed to be smooth and gradually decreasing, similar to the ones of the barium and xenon isotopic chains. Predictions of selected microscopic models are employed for a discussion of the experimental data in the region.

Structural Investigation of Cesium Lead Halide Perovskites for High-Efficiency Quantum Dot Light-Emitting Diodes.

PubMed

Le, Quyet Van; Kim, Jong Beom; Kim, Soo Young; Lee, Byeongdu; Lee, Dong Ryeol

2017-09-07

We have investigated the effect of reaction temperature of hot-injection method on the structural properties of CsPbX 3 (X: Br, I, Cl) perovskite nanocrystals (NCs) using small- and wide-angle X-ray scattering. It is confirmed that the size of the NCs decreased as the reaction temperature decreased, resulting in stronger quantum confinement. The cubic-phase perovskite NCs formed despite the fact that the reaction temperatures increased from 140 to 180 °C; however, monodispersive NC cubes that are required for densely packing self-assembly film were formed only at lower temperatures. From the X-ray scattering measurements, the spin-coated film from more monodispersive perovskite nanocubes synthesized at lower temperatures resulted in more preferred orientation. This dense-packing perovskite film with preferred orientation yielded efficient light-emitting diode (LED) performance. Thus the dense-packing structure of NC assemblies formed after spin-coating should be considered for high-efficient LEDs based on perovskite quantum dots in addition to quantum confinement effect of the quantum dots.

Single-Layer Halide Perovskite Light-Emitting Diodes with Sub-Band Gap Turn-On Voltage and High Brightness.

PubMed

Li, Junqiang; Shan, Xin; Bade, Sri Ganesh R; Geske, Thomas; Jiang, Qinglong; Yang, Xin; Yu, Zhibin

2016-10-03

Charge-carrier injection into an emissive semiconductor thin film can result in electroluminescence and is generally achieved by using a multilayer device structure, which requires an electron-injection layer (EIL) between the cathode and the emissive layer and a hole-injection layer (HIL) between the anode and the emissive layer. The recent advancement of halide perovskite semiconductors opens up a new path to electroluminescent devices with a greatly simplified device structure. We report cesium lead tribromide light-emitting diodes (LEDs) without the aid of an EIL or HIL. These so-called single-layer LEDs have exhibited a sub-band gap turn-on voltage. The devices obtained a brightness of 591 197 cd m -2 at 4.8 V, with an external quantum efficiency of 5.7% and a power efficiency of 14.1 lm W -1 . Such an advancement demonstrates that very high efficiency of electron and hole injection can be obtained in perovskite LEDs even without using an EIL or HIL.

Simplified Perovskite Solar Cell with 4.1% Efficiency Employing Inorganic CsPbBr3 as Light Absorber.

PubMed

Duan, Jialong; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

2018-05-01

Perovskite solar cells with cost-effectiveness, high power conversion efficiency, and improved stability are promising solutions to the energy crisis and environmental pollution. However, a wide-bandgap inorganic-semiconductor electron-transporting layer such as TiO 2 can harvest ultraviolet light to photodegrade perovskite halides, and the high cost of a state-of-the-art hole-transporting layer is an economic burden for commercialization. Here, the building of a simplified cesium lead bromide (CsPbBr 3 ) perovskite solar cell with fluorine-doped tin oxide (FTO)/CsPbBr 3 /carbon architecture by a multistep solution-processed deposition technology is demonstrated, achieving an efficiency as high as 4.1% and improved stability upon interfacial modification by graphene quantum dots and CsPbBrI 2 quantum dots. This work provides new opportunities of building next-generation solar cells with significantly simplified processes and reduced production costs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Short tests to couple N₂O emission mitigation and nitrogen removal strategies for landfill leachate recirculation.

PubMed

Wu, Dong; Wang, Chao; Dolfing, Jan; Xie, Bing

2015-04-15

Landfills implemented with onsite leachate recirculation can efficiently remove pollutants, but currently they are reckoned as N2O emission hot spots. In this project, we evaluated the relationship between N2O emission and nitrogen (N) removal efficiency with different types of leachate recirculated. Nitrate supplemented leachate showed low N2O emission rates with the highest N removal efficiency (~70%), which was equivalent to ~1% nitrogen emitted as N2O. Although in nitrite containing leachates' N removal efficiencies also reached to ~60%, their emitted N2O comprised ~40% of total removed nitrogen. Increasing nitrogen load promoted N2O emission and N removal efficiency, except in ammonia type leachate. When the ratio of BOD to total nitrogen increased from 0.2 to 0.4, the N2O emission flux from nitrate supplemented leachate decreased from ~25 to <0.5 μg N/kg-soil·h. We argue prior to leachate in situ recirculation, sufficient pre-aeration is critical to mitigate N2O surges and simultaneously enhance nitrogen removal efficiency. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 63.4566 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2011 CFR

2011-07-01

... device emission destruction or removal efficiency? 63.4566 Section 63.4566 Protection of Environment... efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test required by § 63.4560...

40 CFR 63.4566 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device emission destruction or removal efficiency? 63.4566 Section 63.4566 Protection of Environment... efficiency? You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test required by § 63.4560...

Application of annular centrifugal contactors in the hot test of the improved total partitioning process for high level liquid waste.

PubMed

Duan, Wuhua; Chen, Jing; Wang, Jianchen; Wang, Shuwei; Feng, Xiaogui; Wang, Xinghai; Li, Shaowei; Xu, Chao

2014-08-15

High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, (90)Sr, (137)Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a CECE (calixcrown ether cesium extraction) process for the removal of Cs, has been developed to treat Chinese HLLW. A 160-hour hot test of the improved total partitioning process was carried out using 72-stage 10-mm-dia annular centrifugal contactors (ACCs) and genuine HLLW. The hot test results showed that the average DFs of total α activity, Sr and Cs were 3.57 × 10(3), 2.25 × 10(4) and 1.68 × 10(4) after the hot test reached equilibrium, respectively. During the hot test, 72-stage 10-mm-dia ACCs worked stable, continuously with no stage failing or interruption of the operation. Copyright © 2014 Elsevier B.V. All rights reserved.

Proceedings of the Chornobyl phytoremediation and biomass energy conversion workshop (in English;Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartley, J.; Tokarevsky, V.

1998-06-01

Many concepts, systems, technical approaches, technologies, ideas, agreements, and disagreements were vigorously discussed during the course of the 2-day workshop. The workshop was successful in generating intensive discussions on the merits of the proposed concept that includes removal of radionuclides by plants and trees (phytoremediation) to clean up soil in the Chornobyl Exclusion Zone (CEZ), use of the resultant biomass (plants and trees) to generate electrical power, and incorporation of ash in concrete casks to be used as storage containers in a licensed repository for low-level waste. Twelve years after the Chornobyl Nuclear Power Plant (ChNPP) Unit 4 accident, whichmore » occurred on April 26, 1986, the primary 4radioactive contamination of concern is from radioactive cesium ({sup 137}Cs) and strontium ({sup 90}Sr). The {sup 137}Cs and {sup 90}Sr were widely distributed throughout the CEZ. The attendees from Ukraine, Russia, Belarus, Denmark and the US provided information, discussed and debated the following issues considerably: distribution and characteristics of radionuclides in CEZ; efficacy of using trees and plants to extract radioactive cesium (Cs) and strontium (Sr) from contaminated soil; selection of energy conversion systems and technologies; necessary infrastructure for biomass harvesting, handling, transportation, and energy conversion; radioactive ash and emission management; occupational health and safety concerns for the personnel involved in this work; and economics. The attendees concluded that the overall concept has technical and possibly economic merits. However, many issues (technical, economic, risk) remain to be resolved before a viable commercial-scale implementation could take place.« less

High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide.

PubMed

Dastidar, Subham; Egger, David A; Tan, Liang Z; Cromer, Samuel B; Dillon, Andrew D; Liu, Shi; Kronik, Leeor; Rappe, Andrew M; Fafarman, Aaron T

2016-06-08

Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.

Synthesis of 4-amino-5-H-2,3-dihydroisothiazole-1,1-dioxide ring systems on sugar templates via carbanion-mediated sulfonamide intramolecular cyclization reactions (CSIC protocols) of glyco-alpha-sulfonamidonitriles.

PubMed

Domínguez, Laura; van Nhien, Albert Nguyen; Tomassi, Cyrille; Len, Christophe; Postel, Denis; Marco-Contelles, José

2004-02-06

The carbanion-mediated sulfonate intramolecular cyclizations (CSIC protocols) of glyco-alpha-sulfonamidonitriles derived from readily available monosaccharides have been extensively investigated using potassium carbonate, cesium carbonate, n-BuLi, and LDA as bases. As a result, a series of enantiomerically pure spiro(4-amino-5-H-2,3-dihydroisothiazole-1,1-dioxide) derivatives have been prepared efficiently and isolated in good yield. The synthesis of these new bicyclic systems is key to accessing a novel range of aza analogues of TSAO nucleosides (ATSAOs).

Enhanced Optical and Electrical Properties of Polymer-Assisted All-Inorganic Perovskites for Light-Emitting Diodes.

PubMed

Ling, Yichuan; Tian, Yu; Wang, Xi; Wang, Jamie C; Knox, Javon M; Perez-Orive, Fernando; Du, Yijun; Tan, Lei; Hanson, Kenneth; Ma, Biwu; Gao, Hanwei

2016-10-01

Highly bright light-emitting diodes based on solution-processed all-inorganic perovskite thin film are demonstrated. The cesium lead bromide (CsPbBr 3 ) created using a new poly(ethylene oxide)-additive spin-coating method exhibits photoluminescence quantum yield up to 60% and excellent uniformity of electrical current distribution. Using the smooth CsPbBr 3 films as emitting layers, green perovskite-based light-emitting diodes (PeLEDs) exhibit electroluminescent brightness and efficiency above 53 000 cd m -2 and 4%: a new benchmark of device performance for all-inorganic PeLEDs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fundamental studies on a heat driven lamp

NASA Technical Reports Server (NTRS)

Lawless, J. L.

1985-01-01

A detailed theoretical study of a heat-driven lamp has been performed. This lamp uses a plasma produced in a thermionic diode. The light is produced by the resonance transition of cesium. An important result of this study is that up to 30% of the input heat is predicted to be converted to light in this device. This is a major improvement over ordinary thermionic energy converters in which only approx. 1% is converted to resonance radiation. Efficiencies and optimum inter-electrode spacings have been found as a function of cathode temperature and the radiative escape factor. The theory developed explains the operating limits of the device.

Role of organic and inorganic cations on thermal behavior of lead iodide perovskites

NASA Astrophysics Data System (ADS)

Singh, Rajan Kumar; Dash, Saumya R.; Kumar, Ranveer; Jain, Neha; Singh, Jai

2018-04-01

Recently, organic-inorganic perovskite materials have attracted much attention due to their enormous potential for use in future of new sustainable energy sources. However, fabrication of environmental friendly perovskite and achieving better stability is a major concern towards the commercialization. Here we study the role of cations in the perovskite powder and their influence upon thermodynamic stability. In this study we find, inorganic (cesium, Cs+) cation is shown to be more efficient in the thermal stabilization of the perovskite material than organic (methylamine, CH3NH2+) cation. This study reviles that stability of perovskite can be improved by incorporation of inorganic cation.

Addition of anaerobic tanks to an oxidation ditch system to enhance removal of phosphorus from wastewater.

PubMed

Liu, Jun-xin; van Groenestijn, J W; Doddema, H J; Wang, Bao-zhen

2002-04-01

The oxidation ditch has been used for many years all over the world as an economic and efficient wastewater treatment technology. It can remove COD, nitrogen and a part of phosphorus efficiently. In the experiment described, a pilot scale Pasveer oxidation ditch system has been tested to investigate the removal of phosphorus from wastewater. The experimental results showed that influent total phosphorus(TP) was removed for 35%-50%. After this, two anaerobic tanks with total volume of 11 m3 were added to the system to release phosphorus. As a result, the TP removal efficiency increased by about 20%. At an anaerobic HRT of about 6 hours, a TP removal efficiency of 71% was achieved.

Efficiency of removal of cadmium from aqueous solutions by plant leaves and the effects of interaction of combinations of leaves on their removal efficiency.

PubMed

Salim, R; Al-Subu, M; Dawod, E

2008-05-01

Removal of cadmium from aqueous solutions using 20 species of plant leaves and combinations of these leaves have been studied. Several factors affecting the removal efficiency have been studied. The most efficient types of plant leaves for the removal of cadmium are those of styrax, plum, pomegranate and walnut. The interaction effect of the combined leaf samples on the efficiency of removal of cadmium has been found to be additive in combinations involving styrax plant leaves but seems to be antagonistic in all other combinations. The optimum experimental conditions for removal of cadmium have been found to be at pH 4.1, using high concentrations of naturally dried plant leaves, using ground leaves and to remove cadmium from agitated aqueous solutions. The percentage of metal removed at an initial cadmium concentration of 10mg/l by the most efficient types of leaves have been found to be 85% for styrax leaves, 85% for plum leaves, 80% for pomegranate leaves, 78% for walnut leaves and 77% for meddler leaves. The presence of foreign ions or complexing agents has been found to reduce the efficiency of removal of cadmium by plant leaves. About 80-85% of the cadmium in charged plant leaves has been released under the influence of changing the pH of the solution, addition of competing ions and the addition of EDTA. The results of removal of cadmium by plant leaves have been found to follow the Freundlich adsorption isotherm, first-order reaction with respect to cadmium and to have intra-pore diffusion as the rate-limiting step.

Deciphering the Measured Ratios of Iodine-131 to Cesium-137 at the Fukushima Reactors

NASA Astrophysics Data System (ADS)

Matsui, T.

2011-12-01

We calculate the relative abundance of the radioactive isotopes Iodine-131 and Cesium-137 produced by nuclear fission in reactors and compare it with data taken at the troubled Fukushima Dai-ichi nuclear power plant. The ratio of radioactivities of these two isotopes can be used to obtain information about when the nuclear reactions terminated.

Scintillator handbook with emphasis on cesium iodide

NASA Technical Reports Server (NTRS)

Tidd, J. L.; Dabbs, J. R.; Levine, N.

1973-01-01

This report provides a background of reasonable depth and reference material on scintillators in general. Particular attention is paid to the cesium iodide scintillators as used in the High Energy Astronomy Observatory (HEAO) experiments. It is intended especially for use by persons such as laboratory test personnel who need to obtain a working knowledge of these materials and their characteristics in a short time.

Electron Temperature Measurements in an Argon/Cesium Plasma Diode.

DTIC Science & Technology

1987-12-01

treatment , Q~xC (E) is modeled as a linear function. Upon viewing the cesium cross section data, one notes that Qmx is reached within only 1 eV of...metal sealIC where the electrode leads enter the cell. Due to the shape of this seal, portions of the glass are exposed to the air, despite the aluminum

X-ray spectrographic determination of cesium and rubidium

USGS Publications Warehouse

Axelrod, J.M.; Adler, I.

1957-01-01

An x-ray spectrographic method for the determination of rubidium and cesium was developed, using the internal-standard method and a four-channel flat-crystal spectrograph. The sensitivity is within 0.1% for cesia and 0.02% for rubidia; the precision is within 10% of the amount present. Results agree well with those obtained by flame photometry and by radio-activation.

Monitoring of electrokinetic removal of heavy metals in tailing-soils using sequential extraction analysis.

PubMed

Kim, S O; Kim, K W

2001-08-17

This research focused on the monitoring of the electrokinetic removal of heavy metals from tailing-soils, and emphasizes the dependency of removal efficiencies upon their physico-chemical states, as demonstrated by the different extraction methods adopted, which included aqua regia and sequential extraction. The tailing-soils examined contained high concentrations of target metal contaminants (Cd=179mgkg(-1), Cu=207mgkg(-1), Pb=5175mgkg(-1), and Zn=7600mgkg(-1)). The removal efficiencies of the different metals were significantly influenced by their speciations, mobilities and affinities (adsorption capacities) in the soil matrix. The removal efficiencies of mobile and weakly bound fractions, such as the exchangeable fraction were more than 90% by electrokinetic treatment, but strongly bound fractions, such as the organically bound species and residual fraction were not significantly removed (less than 30% removal efficiencies). In accordance with the general sequence of mobilities of heavy metals in soils, the removal efficiencies of more mobile heavy metals (Cd, Cu, and Zn) were higher than that of less mobile heavy metal (Pb).

Cesium-Induced Ionic Conduction through a Single Nanofluidic Pore Modified with Calixcrown Moieties.

PubMed

Ali, Mubarak; Ahmed, Ishtiaq; Ramirez, Patricio; Nasir, Saima; Cervera, Javier; Mafe, Salvador; Niemeyer, Christof M; Ensinger, Wolfgang

2017-09-12

We demonstrate experimentally and theoretically a nanofluidic device for the selective recognition of the cesium ion by exploiting host-guest interactions inside confined geometry. For this purpose, a host molecule, i.e., the amine-terminated p-tert-butylcalix[4]arene-crown (t-BuC[4]C-NH 2 ), is successfully synthesized and functionalized on the surface of a single conical nanopore fabricated in a poly(ethylene terephthalate) (PET) membrane through carbodiimide coupling chemistry. On exposure to the cesium cation, the t-BuC[4]C-Cs + complex is formed through host-guest interaction, leading to the generation of positive fixed charges on the pore surface. The asymmetrical distribution of these groups along the conical nanopore leads to the electrical rectification observed in the current-voltage (I-V) curve. On the contrary, other alkali cations are not able to induce any significant change in the rectification characteristics of the nanopore. The success of the chemical modification is monitored from the changes in the electrical readout of the nanopore. Theoretical results based on the Nernst-Planck and Poisson equations further demonstrate the validity of the experimental approach to the cesium-induced ionic conduction of the nanopore.

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

NASA Astrophysics Data System (ADS)

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.

Hydrogen masers and cesium fountains at NRC

NASA Technical Reports Server (NTRS)

Boulanger, J.-S.; Morris, D.; Douglas, R. J.; Gagne, M.-C.

1994-01-01

The NRC masers H-3 and H-4 have been operating since June 1993 with cavity servo control. These low-flux active H masers are showing stabilities of about 10(exp -15) from 1 hour to several days. Stability results are presented, and the current and planned uses of the masers are discussed. A cesium fountain primary frequency standard project has been started at NRC. Trapping and launching experiments with the goal of 7 m/s launches are beginning. We discuss our plans for a local oscillator and servo that exploit the pulsed aspect of cesium fountain standards, and meet the challenge of 10(exp -14) tau(exp -1/2) stability without requiring masers. At best, we expect to run this frequency standard initially for periods of hours each working day rather than continuously for years, and so frequency transfer to outside laboratories has been carefully considered. We conclude that masers (or other even better secondary clocks) are required to exploit this potential accuracy of the cesium fountain. We present and discuss our conclusion that it is feasible to transfer frequency in this way with a transfer-induced uncertainty of less than 10(exp -15), even in the presence of maser frequency drift and random walk noise.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD. [energy conversion efficiency of electric power plants using magnetohydrodynamics

NASA Technical Reports Server (NTRS)

Tsu, T. C.

1976-01-01

A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to give a topping cycle efficiency of 59.3%; however when combined with an integrated gasifier and optimistic steam bottomer the coal to bus bar efficiency drops to 45.5%. A 1978 K (3100 F) cycle has an efficiency of 55.1% and a power plant efficiency of 42.2%. The high cost of the external heating loop components results in a cost of electricity of 21.41 mills/MJ (77.07 mills/kWh) for the high temperature system and 19.0 mills/MJ (68.5 mills/kWh) for the lower temperature system. It is, therefore, thought that this cycle may be more applicable to internally heated systems such as some futuristic high temperature gas cooled reactor.

Wastewater treatment for nutrient removal with Ecuadorian native microalgae.

PubMed

Benítez, María Belén; Champagne, Pascale; Ramos, Ana; Torres, Andres F; Ochoa-Herrera, Valeria

2018-04-12

The aim of this project was to study the feasibility of utilizing native microalgae for the removal of nitrogen and phosphorus, as a potential secondary wastewater treatment process in Ecuador. Agitation and aeration batch experiments were conducted using synthetic secondary wastewater effluent, to determine nitrogen and phosphorus removal efficiencies by a native Ecuadorian microalgal strain. Experimental results indicated that microalgal cultures could successfully remove nitrogen and phosphorus. [Formula: see text] and [Formula: see text] removal efficiencies of 52.6 and 55.6%, and 67.0 and 20.4%, as well as [Formula: see text] production efficiencies of 87.0 and 93.1% were reported in agitation and aeration photobioreactors, respectively. Aeration was not found to increase the nutrient removal efficiency of [Formula: see text]. Moreover, in the case of [Formula: see text], a negative impact was observed, where removal efficiencies decreased by a factor of 3.3 at higher aeration rates. To the best of our knowledge, this is the first report of the removal of nutrients by native Ecuadorian Chlorella sp., hence the results of this study would indicate that this native microalgal strain could be successfully incorporated in a potential treatment process for nutrient removal in Ecuador.

Characterization of the March 2017 tank 10 surface sample (combination of HTF-10-17-30 AND HTF-10-17-31) and variable depth sample (combination of HTF-10-17-32 and HTF-10-17-33)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reboul, S. H.

Two surface samples (HTF-10-17-30 and HTF-10-17-31) and two variable depth samples (HTF-10-17-32 and HTF-10-17-33) were collected from SRS Tank 10 during March 2017 and submitted to SRNL for characterization. At SRNL, the two surface samples were combined in one container, the two variable depth samples (VDSs) were combined in another container, and then the two composite samples were each characterized by a series of physical, ionic, radiological, and elemental analysis methods. The surface sample composite was characterized primarily for Tank Farm corrosion control purposes, while the VDS composite was characterized primarily for Tank Closure Cesium Removal (TCCR) purposes.

Realization of a twin beam source based on four-wave mixing in Cesium

NASA Astrophysics Data System (ADS)

Adenier, G.; Calonico, D.; Micalizio, S.; Samantaray, N.; Degiovanni, I. P.; Berchera, I. Ruo

2016-05-01

Four-wave mixing (4WM) is a known source of intense non-classical twin beams. It can be generated when an intense laser beam (the pump) and a weak laser beam (the seed) overlap in a χ(3) medium (here Cesium vapor), with frequencies close to resonance with atomic transitions. The twin beams generated by 4WM have frequencies naturally close to atomic transitions, and can be intense (gain ≫1) even in the CW pump regime, which is not the case for PDC χ(2) phenomenon in nonlinear crystals. So, 4WM is well suited for atom-light interaction and atom-based quantum-protocols. Here, we present the first realization of a source of 4-wave mixing exploiting D2 line of Cesium atoms.

Monitoring Cs-134 and 137 released by Fukushima Dai-ichi Nuclear Power Plant accident in ground, soil, and stream waters

NASA Astrophysics Data System (ADS)

Tsujimura, Maki; Onda, Yuichi; Hada, Manami; Ishwar, Pun; Abe, Yutaka

2013-04-01

Due to Fukushima Dai-ichi Nuclear power plant accident occurred in March 2011, large amount of radionuclides was released into the atmosphere and was fallen onto ground by rainfall. Few researches have monitored radioactive cesium dynamics in whole hydrological cycle system such as groundwater, soil water, spring water and stream water. Thus, the purpose of this study is to monitor concentration of radioactive cesium in those waters in time series in the headwaters. We have performed an intensive monitoring at three small mountainous catchments in Yamakiya district, Kawamata town, Fukushima prefecture, locating 35 km northwest from Fukushima Dai-ichi Nuclear Power Plant since June 2011, also we consider the movement of radioactive cesium and its relation with the hydrological cycle.

Cs 62 DJ Rydberg-atom macrodimers formed by long-range multipole interaction

NASA Astrophysics Data System (ADS)

Han, Xiaoxuan; Bai, Suying; Jiao, Yuechun; Hao, Liping; Xue, Yongmei; Zhao, Jianming; Jia, Suotang; Raithel, Georg

2018-03-01

Long-range macrodimers formed by D -state cesium Rydberg atoms are studied in experiments and calculations. Cesium [62DJ]2 Rydberg-atom macrodimers, bonded via long-range multipole interaction, are prepared by two-color photoassociation in a cesium atom trap. The first color (pulse A) resonantly excites seed Rydberg atoms, while the second (pulse B, detuned by the molecular binding energy) resonantly excites the Rydberg-atom macrodimers below the [62DJ]2 asymptotes. The molecules are measured by extraction of autoionization products and Rydberg-atom electric-field ionization, and ion detection. Molecular spectra are compared with calculations of adiabatic molecular potentials. From the dependence of the molecular signal on the detection delay time, the lifetime of the molecules is estimated to be 3 -6 μ s .

The analysis of isotherms of radionuclides sorption by inorganic sorbents

NASA Astrophysics Data System (ADS)

Bykova, E. P.; Nedobukh, T. A.

2017-09-01

The isotherm of cesium sorption by an inorganic sorbent based on granulated glauconite obtained in a wide cesium concentrations range was mathematically treated using Langmuir, Freundlich and Redlich-Peterson sorption models. The algorithms of mathematical treatment of experimental data using these models were described; parameters of all isotherms were determined. It was shown that estimating the correctness of various sorption models relies not only on the correlation coefficient values but also on the closeness of the calculated and experimental data. Various types of sorption sites were found as a result of mathematical treatment of the isotherm of cesium sorption. The algorithm was described and calculation of parameters of the isotherm was performed under the assumption that simultaneous sorption on all three types of sorption sites occurs in accordance with Langmuir isotherm.

Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.

PubMed

Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

2013-09-01

In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates. Copyright © 2013 Elsevier Ltd. All rights reserved.

Study on removal efficiency of nitrogen and phosphorus from agricultural wastewater by subsurface flow constructed wetland

NASA Astrophysics Data System (ADS)

Ling, Zhen; Li, Jie

2018-03-01

Subsurface Flow Constructed Wetland Plant 5 kinds of perennial herbs, there are Canna, Water onion, Iris, Calamus, Reed. Foucs on Subsurface Flow Constructed Wetlands on agricultural wastewater nitrogen and phosphorus removal effect. Research results: Different plants TP removal efficiency from high to low is Iris> reed> calamus> water onion> canna.And TN removal efficiency from high to low is reed> water onion> iris> calamus> canna. Compared with the blank test land, Wetland plants improves TN removal and TP removal is higher than TN. Wetland plants can reduce the PH of experimental water.

Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

PubMed

Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

2012-04-01

Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (p<0.05) enhancement in planted beds as compared to the unplanted beds. Removal of caffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Application of steel slag coated with sodium hydroxide to enhance precipitation-coagulation for phosphorus removal.

PubMed

Park, Taejun; Ampunan, Vanvimol; Maeng, Sungkyu; Chung, Eunhyea

2017-01-01

Phosphorus removal has been studied for decades to reduce the environmental impact of phosphorus in natural waterbodies. Slag has been applied for the phosphorus removal by several mechanisms. In this study, sodium hydroxide coating was applied on the slag surface to enhance the efficiency of precipitation-coagulation process. In the batch test, it was found that the capacity of the slag to maintain high pH decreases with increasing its exposure time to the aqueous solution. In the column test, the coarse-grained coated slag showed higher phosphorus removal efficiency than the fine-grained uncoated slag. The coated slag maintained pH higher than uncoated slag and, accordingly, the removal efficiency of phosphorus was higher. Especially, when pH was less than 8, the removal efficiency decreased significantly. However, coated slag provided an excess amount of aluminum and sodium. Thus, a return process to reuse aluminum and sodium as a coagulant was introduced. The return process yields longer lifespan of slag with higher phosphorus removal and lower concentration of cations in the effluent. With the return process, the phosphorus removal efficiency was kept higher than 60% until 150 bed volumes; meanwhile, the efficiency without return process became lower than 60% at 25 bed volumes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decolourization of remazol black-5 textile dyes using moving bed bio-film reactor

NASA Astrophysics Data System (ADS)

Pratiwi, R.; Notodarmojo, S.; Helmy, Q.

2018-01-01

The desizing and dyeing processes in the textile industries produces wastewaster containing high concentration of organic matter and colour, so it needs treatment before released to environment. In this research, removal of azo dye (Remazol Black 5/RB 5) and organic as COD was performed using Moving Bed Biofilm Reactor (MBBR). MBBR is biological treatment process with attached growth media system that can increase removal of organic matter in textile wastewater. The effectiveness of ozonation as pre-treatment process to increase the removal efficiency in MBBR was studied. The results showed that in MBBR batch system with detention time of 1 hour, pre-treatment with ozonation prior to MBBR process able to increase the colour removal efficiency of up to 86.74%. While on the reactor without ozone pre-treatment, the colour removal efficiency of up to 68.6% was achieved. From the continuous reactor experiments found that both colour and COD removal efficiency depends on time detention of RB-5 dyes in the system. The higher of detention time, the higher of colour and COD removal efficiency. It was found that optimum removal of colour and COD was achieved in 24 hour detention time with its efficiency of 96.9% and 89.13%, respectively.

0D-2D and 1D-2D Semiconductor Hybrids Composed of All Inorganic Perovskite Nanocrystals and Single-Layer Graphene with Improved Light Harvesting

DOE PAGES

Chen, Jia-Shiang; Doane, Tennyson L.; Li, Mingxing; ...

2017-12-27

In this study, inorganic cesium lead iodide (CsPbI 3) perovskite nanoparticles (PNPs) and perovskite nanowires (PNWs) with single-layer graphene (SLG) are combined to obtain 0D–2D PNP–SLG and 1D–2D PNW–SLG hybrids with improved light harvesting. Time-resolved single-nanostructure photoluminescence studies of PNPs, PNWs, and related hybrids reveal (i) quasi-two-state photoluminescence blinking in PNPs, (ii) highly polarized photoluminescence emitted by PNWs and (iii) efficient interfacial electron transfer between perovskite nanostructures and SLG in both PNP–SLG and PNW–SLG hybrids. Thus, doping of poorly absorbing, highly conductive SLG with perovskite nanocrystals and nanowires provides a simple, yet efficient path to obtain hybrids with increased light-harvestingmore » properties for potential utilization in the next-generation photodetectors and photovoltaic devices, including polarization sensitive photodetectors.« less

0D-2D and 1D-2D Semiconductor Hybrids Composed of All Inorganic Perovskite Nanocrystals and Single-Layer Graphene with Improved Light Harvesting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jia-Shiang; Doane, Tennyson L.; Li, Mingxing

In this study, inorganic cesium lead iodide (CsPbI 3) perovskite nanoparticles (PNPs) and perovskite nanowires (PNWs) with single-layer graphene (SLG) are combined to obtain 0D–2D PNP–SLG and 1D–2D PNW–SLG hybrids with improved light harvesting. Time-resolved single-nanostructure photoluminescence studies of PNPs, PNWs, and related hybrids reveal (i) quasi-two-state photoluminescence blinking in PNPs, (ii) highly polarized photoluminescence emitted by PNWs and (iii) efficient interfacial electron transfer between perovskite nanostructures and SLG in both PNP–SLG and PNW–SLG hybrids. Thus, doping of poorly absorbing, highly conductive SLG with perovskite nanocrystals and nanowires provides a simple, yet efficient path to obtain hybrids with increased light-harvestingmore » properties for potential utilization in the next-generation photodetectors and photovoltaic devices, including polarization sensitive photodetectors.« less

303 nm continuous wave ultraviolet laser generated by intracavity frequency-doubling of diode-pumped Pr3+:LiYF4 laser

NASA Astrophysics Data System (ADS)

Zhu, Pengfei; Zhang, Chaomin; Zhu, Kun; Ping, Yunxia; Song, Pei; Sun, Xiaohui; Wang, Fuxin; Yao, Yi

2018-03-01

We demonstrate an efficient and compact ultraviolet laser at 303 nm generated by intracavity frequency doubling of a continuous wave (CW) laser diode-pumped Pr3+:YLiF4 laser at 607 nm. A cesium lithium borate (CLBO) crystal, cut for critical type I phase matching at room temperature, is used for second-harmonic generation (SHG) of the fundamental laser. By using an InGaN laser diode array emitting at 444.3 nm with a maximum incident power of 10 W, as high as 68 mW of CW output power at 303 nm is achieved. The output power stability in 4 h is better than 2.85%. To the best of our knowledge, this is high efficient UV laser generated by frequency doubling of an InGaN laser diode array pumped Pr3+:YLiF4 laser.

Using Wet-FGD systems for mercury removal.

PubMed

Díaz-Somoano, Mercedes; Unterberger, Sven; Hein, Klaus R G

2005-09-01

A plan to control mercury emissions to the atmosphere and to establish mercury emission limits has recently been elaborated by the European Commission, making it necessary to devise an efficient and cost effective mercury removal technology. Towards this end wet flue gas desulfurization units appear as a promising option for multi-pollutant control. However, more investigation on mercury removal and a greater mercury removal efficiency are required to achieve this objective. In the present work scrubber chemistry and the application of various solid additives to enhance mercury removal in wet scrubbers is evaluated. The results obtained show a significant correlation between mercury removal efficiency and the pH of the scrubber slurry and SO2 concentration. A weaker correlation was observed between oxygen or slurry concentration and removal efficiency. Finally several solid oxides were found to be effective additives for enhancing mercury capture in wet scrubbers.

Removal of particulate matter emitted from a subway tunnel using magnetic filters.

PubMed

Son, Youn-Suk; Dinh, Trieu-Vuong; Chung, Sang-Gwi; Lee, Jai-Hyo; Kim, Jo-Chun

2014-01-01

We removed particulate matter (PM) emitted from a subway tunnel using magnetic filters. A magnetic filter system was installed on the top of a ventilation opening. Magnetic field density was increased by increasing the number of permanent magnet layers to determine PM removal characteristics. Moreover, the fan's frequency was adjusted from 30 to 60 Hz to investigate the effect of wind velocity on PM removal efficiency. As a result, PM removal efficiency increased as the number of magnetic filters or fan frequency increased. We obtained maximum removal efficiency of PM10 (52%), PM2.5 (46%), and PM1 (38%) at a 60 Hz fan frequency using double magnetic filters. We also found that the stability of the PM removal efficiency by the double filter (RSD, 3.2-5.8%) was higher than that by a single filter (10.9-24.5%) at all fan operating conditions.

Extraction of cesium and strontium from nuclear waste

DOEpatents

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.

Diminiode thermionic energy conversion with lanthanum-hexaboride electrodes

NASA Technical Reports Server (NTRS)

Kroeger, E. W.; Bair, V. L.; Morris, J. F.

1978-01-01

Thermionic conversion data obtained from a variable gap cesium diminiode with a hot pressed, sintered lanthanum hexaboride emitter and an arc melted lanthanum hexaboride collector are presented. Performance curves cover a range of temperatures: emitter 1500 to 1700 K, collector 750 to 1000 K, and cesium reservoir 370 to 510 K. Calculated values of emitter and collector work functions and barrier index are also given.

Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater.

PubMed

Zhao, Qian; Han, Hongjun; Xu, Chunyan; Zhuang, Haifeng; Fang, Fang; Zhang, Linghan

2013-08-01

A combined process consisting of a powdered activated carbon technology (PACT) and short-cut biological nitrogen removal reactor (SBNR) was developed to enhance the removal efficiency of the total nitrogen (TN) from the effluent of an upflow anaerobic sludge bed (UASB) reactor, which was used to treat coal gasification wastewater (CGW). The SBNR performance was improved with the increasing of COD and TP removal efficiency via PACT. The average removal efficiencies of COD and TP in PACT were respectively 85.80% and 90.30%. Meanwhile, the NH3-N to NO2-N conversion rate was achieved 86.89% in SBNR and the total nitrogen (TN) removal efficiency was 75.54%. In contrast, the AOB in SBNR was significantly inhibited without PACT or with poor performance of PACT in advance, which rendered the removal of TN. Furthermore, PAC was demonstrated to remove some refractory compounds, which therefore improved the biodegradability of the coal gasification wastewater. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Application of Colloidal Filtration Theory on Textile Fibrous Media: Effect of Fiber Orientation on Bacterial Removal Efficiency and Attachment

NASA Astrophysics Data System (ADS)

Roy, Sukumar; Ghosh, Subrata; Bhowmick, Niranjan

2018-06-01

A mechanism to remove the Pseudomonas bacteria from contaminated water by using textile fibrous media has been proposed in this article. The attachment of Pseudomonas bacteria on nylon fibrous media was studied in laboratory column experiment. A systematic study was carried out to investigate the attachment of bacteria on the fibrous material as a function of fiber orientation to the direction of the liquid flow. Three types of textiles media with different orientation fiber were selected for the experiment (i.e. 0°, 45° and 90°). It was found that the bacteria removal efficiency was comparatively higher at 90° orientation as compared to that of 45° and 0° orientation of fibrous media, suggesting that the removal efficiency of bacteria (1 - Fp) was depended on fiber orientation. The removal trends were explained on the basis of colloidal filtration theory. This is due to the higher single collector contact efficiency and attachment/collision efficiency as observed from the experimental data of removal efficiency.

Application of Colloidal Filtration Theory on Textile Fibrous Media: Effect of Fiber Orientation on Bacterial Removal Efficiency and Attachment

NASA Astrophysics Data System (ADS)

Roy, Sukumar; Ghosh, Subrata; Bhowmick, Niranjan

2018-05-01

A mechanism to remove the Pseudomonas bacteria from contaminated water by using textile fibrous media has been proposed in this article. The attachment of Pseudomonas bacteria on nylon fibrous media was studied in laboratory column experiment. A systematic study was carried out to investigate the attachment of bacteria on the fibrous material as a function of fiber orientation to the direction of the liquid flow. Three types of textiles media with different orientation fiber were selected for the experiment (i.e. 0°, 45° and 90°). It was found that the bacteria removal efficiency was comparatively higher at 90° orientation as compared to that of 45° and 0° orientation of fibrous media, suggesting that the removal efficiency of bacteria (1 - Fp) was depended on fiber orientation. The removal trends were explained on the basis of colloidal filtration theory. This is due to the higher single collector contact efficiency and attachment/collision efficiency as observed from the experimental data of removal efficiency.

Photoelectron spectroscopy of color centers in negatively charged cesium iodide nanocrystals

NASA Astrophysics Data System (ADS)

Sarkas, Harry W.; Kidder, Linda H.; Bowen, Kit H.

1995-01-01

We present the photoelectron spectra of negatively charged cesium iodide nanocrystals recorded using 2.540 eV photons. The species examined were produced using an inert gas condensation cluster ion source, and they ranged in size from (CsI)-n=13 to nanocrystal anions comprised of 330 atoms. Nanocrystals showing two distinct types of photoemission behavior were observed. For (CsI)-n=13 and (CsI)-n=36-165, a plot of cluster anion photodetachment threshold energies vs n-1/3 gives a straight line extrapolating (at n-1/3=0, i.e., n=∞) to 2.2 eV, the photoelectric threshold energy for F centers in bulk cesium iodide. The linear extrapolation of the cluster anion data to the corresponding bulk property implies that the electron localization in these gas-phase nanocrystals is qualitatively similar to that of F centers in extended alkali halide crystals. These negatively charged cesium iodide nanocrystals are thus shown to support embryonic forms of F centers, which mature with increasing cluster size toward condensed phase impurity centers. Under an alternative set of source conditions, nanocrystals were produced which showed significantly lower photodetachment thresholds than the aforementioned F-center cluster anions. For these species, containing 83-131 atoms, a plot of their cluster anion photodetachment threshold energies versus n-1/3 gives a straight line which extrapolates to 1.4 eV. This value is in accord with the expected photoelectric threshold energy for F' centers in bulk cesium iodide, i.e., color centers with two excess electrons in a single defect site. These nanocrystals are interpreted to be the embryonic F'-center containing species, Cs(CsI)-n=41-65.

Investigation of the unusual behavior of cesium-137 and other radionuclides in the Florida environment. Progress report, September 1, 1975--August 31, 1976. [Digitaria decumbens, Paspalum notatum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamble, J.F.

1976-01-01

The most significant development in the contract year was the documentation of the presence of endomycorrhizal, vesicular arbuscular (V-A) mycorrhizae in the pasture systems of south Florida that have the elevated levels of cesium-137 activity. In all samples the V-A hyphal network was well developed and growing throughout the particles of organic matter. The organic particles are held in a loose, aggregate structure by the hyphal network. In improved pastures of Digitaria decumbens (pangola) and Paspalum notatum (bahiagrass) the root infection ranged from 24 to 95 percent. The principle association was Gigaspora and Glomus sp. In the unimproved pastures ofmore » mostly Aristida stricta (wiregrass) and Serenoa repens (saw palmetto) the infection was 70 percent and only Acaulospora laevis was found. Experiments are in progress to show whether there are differences in cesium uptake between mycorrhizal and non-mycorrhizal grass plants. The test grass is pangola. Greenhouse tests involve V-A mycorrhizal control using a fungicide, the infection of grass cuttings with mycorrhizal strains found in the test area. These pot experiments will serve as pilot programs for field experiments. The effects of ectomycorrhizal associations on uptake of cesium in pine seedlings is also being studied. Analysis of the dynamics of organic matter cycling in a mesic hardwood forest shows that the rates of organic matter flow are similar to tropical systems although the plant species are warm temperate. The increased tempo of organic turnover probably contributes to the observed higher-than-expected levels of cesium-137 activity in Florida biosystems.« less

Assessment of urinary metals following exposure to a large vegetative fire, New Mexico, 2000.

PubMed

Wolfe, Mitchell I; Mott, Joshua A; Voorhees, Ronald E; Sewell, C Mack; Paschal, Dan; Wood, Charles M; McKinney, Patrick E; Redd, Stephen

2004-03-01

In May 2000, a vegetative fire burned 47,000 acres in northern New Mexico, including 7500 acres of land administered by the Los Alamos National Laboratory. We evaluated potential human exposures from the fire. We surveyed two populations (firefighters and the general population) in four cities for urine heavy metal concentrations. Reference concentrations were based on the Third National Health and Nutrition Examination Survey (NHANES III). Multivariate linear regression assessed the association of urinary metal concentrations with smoke exposure. We also performed isotopic analysis of uranium and cesium on a subset of specimens. A total of 92 firefighters and 135 nonfirefighters participated. In both populations, urinary nickel, cesium, chromium, and uranium concentrations were greater than expected compared with NHANES III reference values. No values required immediate medical follow-up. Regression analysis demonstrated that for National Guard members, arsenic and cadmium levels were significantly related to smoke exposure, and for firefighters, cesium and arsenic levels were significantly related to exposure; however, only for cesium in National Guard members was this association in the positive direction. Isotopic analysis demonstrated that the cesium and uranium were naturally occurring. Some people had spot urine metal concentrations above nationally derived reference values, and values for some metals were associated with smoke exposure. These associations had little public health or clinical importance. Studies of exposures resulting from vegetative fires are difficult, and careful consideration should be given to the technical and communication processes at the outset of a fire exposure investigation. Recommendations for future investigations include testing as soon as possible during or after a fire, and early clinical consultation with a medical toxicologist.

Colloid-facilitated mobilization of metals by freeze-thaw cycles.

PubMed

Mohanty, Sanjay K; Saiers, James E; Ryan, Joseph N

2014-01-21

The potential of freeze-thaw cycles to release colloids and colloid-associated contaminants into water is unknown. We examined the effect of freeze-thaw cycles on the mobilization of cesium and strontium in association with colloids in intact cores of a fractured soil, where preferential flow paths are prevalent. Two intact cores were contaminated with cesium and strontium. To mobilize colloids and metal cations sequestered in the soil cores, each core was subjected to 10 intermittent wetting events separated by 66 h pauses. During the first five pauses, the cores were dried at room temperature, and during last five pauses, the cores were subjected to 42 h of freezing followed by 24 h of thawing. In comparison to drying, freeze-thaw cycles created additional preferential flow paths through which colloids, cesium, and strontium were mobilized. The wetting events following freeze-thaw intervals mobilized about twice as many colloids as wetting events following drying at room temperature. Successive wetting events following 66 h of drying mobilized similar amounts of colloids; in contrast, successive wetting events after 66 h of freeze-thaw intervals mobilized greater amounts of colloids than the previous one. Drying and freeze-thaw treatments, respectively, increased and decreased the dissolved cesium and strontium, but both treatments increased the colloidal cesium and strontium. Overall, the freeze-thaw cycles increased the mobilization of metal contaminants primarily in association with colloids through preferential flow paths. These findings suggest that the mobilization of colloid and colloid-associated contaminants could increase when temperature variations occur around the freezing point of water. Thus, climate extremes have the potential to mobilize contaminants that have been sequestered in the vadose zone for decades.

Detection of the actinides and cesium from environmental samples

NASA Astrophysics Data System (ADS)

Snow, Mathew Spencer

Detection of the actinides and cesium in the environment is important for a variety of applications ranging from environmental remediation to safeguards and nuclear forensics. The utilization of multiple different elemental concentrations and isotopic ratios together can significantly improve the ability to attribute contamination to a unique source term and/or generation process; however, the utilization of multiple elemental "signatures" together from environmental samples requires knowledge of the impact of chemical fractionation for various elements under a variety of environmental conditions (including predominantly aqueous versus arid conditions). The research reported in this dissertation focuses on three major areas: 1. Improving the understanding of actinide-mineral interactions at ultra-low concentrations. Chapter 2 reports a batch sorption and modeling study of Np(V) sorption to the mineral goethite from attomolar to micromolar concentrations. 2. Improving the detection capabilities for Thermal Ionization Mass Spectrometry (TIMS) analyses of ultra-trace cesium from environmental samples. Chapter 4 reports a new method which significantly improves the chemical yields, purification, sample processing time, and ultimately, the detection limits for TIMS analyses of femtogram quantities of cesium from a variety of environmental sample matrices. 3. Demonstrating how actinide and cesium concentrations and isotopic ratios from environmental samples can be utilized together to determine a wealth of information including environmental transport mechanisms (e.g. aqueous versus arid transport) and information on the processes which generated the original material. Chapters1, 3 and 5 demonstrate these principles using Pu, Am, Np, and Cs concentrations and isotopic ratios from contaminated soils taken near the Subsurface Disposal Area (SDA) of Idaho National Laboratory (INL) (a low level radioactive waste disposal site in southeastern Idaho).

Effects of influent C/N ratios and treatment technologies on integral biogas upgrading and pollutants removal from synthetic domestic sewage.

PubMed

Xu, Jie; Wang, Xue; Sun, Shiqing; Zhao, Yongjun; Hu, Changwei

2017-09-07

Three different treatment technologies, namely mono-algae culture, algal-bacterial culture, and algal-fungal culture, were applied to remove pollutants form synthetic domestic sewage and to remove CO 2 from biogas in a photobioreactor. The effects of different initial influent C/N ratios on microalgal growth rates and pollutants removal efficiencies by the three microalgal cultures were investigated. The best biogas upgrading and synthetic domestic sewage pollutants removal effect was achieved in the algal-fungal system at the influent C/N ratio of 5:1. At the influent C/N ratio of 5:1, the algal-fungal system achieved the highest mean chemical oxygen demand (COD) removal efficiency of 81.92% and total phosphorus (TP) removal efficiency of 81.52%, respectively, while the algal-bacterial system demonstrated the highest mean total nitrogen (TN) removal efficiency of 82.28%. The average CH 4 concentration in upgraded biogas and the removal efficiencies of COD, TN, and TP were 93.25 ± 3.84% (v/v), 80.23 ± 3.92%, 75.85 ± 6.61%, and 78.41 ± 3.98%, respectively. These results will provide a reference for wastewater purification ad biogas upgrading with microalgae based technology.

Nanocrystals of Cesium Lead Halide Perovskites (CsPbX₃, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut.

PubMed

Protesescu, Loredana; Yakunin, Sergii; Bodnarchuk, Maryna I; Krieg, Franziska; Caputo, Riccarda; Hendon, Christopher H; Yang, Ruo Xi; Walsh, Aron; Kovalenko, Maksym V

2015-06-10

Metal halides perovskites, such as hybrid organic-inorganic CH3NH3PbI3, are newcomer optoelectronic materials that have attracted enormous attention as solution-deposited absorbing layers in solar cells with power conversion efficiencies reaching 20%. Herein we demonstrate a new avenue for halide perovskites by designing highly luminescent perovskite-based colloidal quantum dot materials. We have synthesized monodisperse colloidal nanocubes (4-15 nm edge lengths) of fully inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) using inexpensive commercial precursors. Through compositional modulations and quantum size-effects, the bandgap energies and emission spectra are readily tunable over the entire visible spectral region of 410-700 nm. The photoluminescence of CsPbX3 nanocrystals is characterized by narrow emission line-widths of 12-42 nm, wide color gamut covering up to 140% of the NTSC color standard, high quantum yields of up to 90%, and radiative lifetimes in the range of 1-29 ns. The compelling combination of enhanced optical properties and chemical robustness makes CsPbX3 nanocrystals appealing for optoelectronic applications, particularly for blue and green spectral regions (410-530 nm), where typical metal chalcogenide-based quantum dots suffer from photodegradation.

Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previousmore » ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siekhaus, W. J.; Teslich, N. E.; Weber, P. K.

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 implantationmore » and sputter-erosion of uranium and uranium carbide were calculated to be U₈₆Ga₁₄, (UC)₇₀Ga₃₀ and U₈₁Cs₉, (UC)₇₉Cs₂₁, respectively.« less

Technical Improvements to an Absorbing Supergel for Radiological Decontamination in Tropical Environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaminski, Michael D.; Mertz, Carol J.; Kivenas, Nadia

Argonne National Laboratory (Argonne) developed a superabsorbing gel-based process (SuperGel) for the decontamination of cesium from concrete and other porous building materials. Here, we report on results that tested the gel decontamination technology on specific concrete and ceramic formulations from a coastal city in Southeast Asia, which may differ significantly from some U.S. sources. Results are given for the evaluation of americium and cesium sequestering agents that are commercially available at a reasonable cost; the evaluation of a new SuperGel formulation that combines the decontamination properties of cesium and americium; the variation of the contamination concentration to determine the effectsmore » on the decontamination factors with concrete, tile, and brick samples; and pilot-scale testing (0.02–0.09 m2 or 6–12 in. square coupons).« less

A testing-coverage software reliability model considering fault removal efficiency and error generation.

PubMed

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance.

Behavior of pharmaceuticals in waste water treatment plant in Japan.

PubMed

Matsuo, H; Sakamoto, H; Arizono, K; Shinohara, R

2011-07-01

The fate of pharmaceuticals in a wastewater treatment plant (WWTP) in Kumamoto, Japan with activated sludge treatment is reported. Selected pharmaceuticals were detected in influent. Results from the present study confirmed that Acetaminophen, Amoxicillin, Ampicillin and Famotidine were removed at a high rate (>90% efficiency). In contrast, removal efficiency of Ketoprofen, Losartan, Oseltamivir, Carbamazepine, and Diclofenac was relatively low (<50%). The selected pharmaceuticals were also detected in raw sludge. In digestive process, Indomethacin, Atenolol, Famotidine, Trimethoprim and Cyclofosamide were removed at a high (>70% efficiency). On the other hand, removal of Carbamazepine, Ketoprofen and Diclofenac was not efficient (<50%).

Effect of some operational parameters on the arsenic removal by electrocoagulation using iron electrodes

PubMed Central

2014-01-01

Arsenic contamination of drinking water is a global problem that will likely become more apparent in future years as scientists and engineers measure the true extent of the problem. Arsenic poisoning is preventable though as there are several methods for easily removing even trace amounts of arsenic from drinking water. In the present study, electrocoagulation was evaluated as a treatment technology for arsenic removal from aqueous solutions. The effects of parameters such as initial pH, current density, initial concentration, supporting electrolyte type and stirring speed on removal efficiency were investigated. It has been observed that initial pH was highly effective on the arsenic removal efficiency. The highest removal efficiency was observed at initial pH = 4. The obtained experimental results showed that the efficiency of arsenic removal increased with increasing current density and decreased with increasing arsenic concentration in the solution. Supporting electrolyte had not significant effects on removal, adding supporting electrolyte decreased energy consumption. The effect of stirring speed on removal efficiency was investigated and the best removal efficiency was at the 150 rpm. Under the optimum conditions of initial pH 4, current density of 0.54 mA/cm2, stirring speed of 150 rpm, electrolysis time of 30 minutes, removal was obtained as 99.50%. Energy consumption in the above conditions was calculated as 0.33 kWh/m3. Electrocoagulation with iron electrodes was able to bring down 50 mg/L arsenic concentration to less than 10 μg/L at the end of electrolysis time of 45 minutes with low electrical energy consumption as 0.52 kWh/m3. PMID:24991426

Extraction of cesium and strontium from nuclear waste

DOEpatents

Davis, M.W. Jr.; Bowers, C.B. Jr.

1988-06-07

Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4[prime](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[prime](5[prime]) [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution. 3 figs.

Fire Safety Tests for Cesium-Loaded Spherical Resorcinol Formaldehyde Resin: Data Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong-Sang; Schweiger, Michael J.; Peterson, Reid A.

2012-09-01

A draft safety evaluation of the scenario for spherical resorcinol formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping. To resolve this question, the fire properties of the SRF resin were measured by Southwest Research Institute (SwRI) through a subcontract managed by Pacific Northwest National Laboratory (PNNL). The results of initial fire safety tests on themore » SRF resin were documented in a previous report (WTP-RPT-218). The present report summarizes the results of additional tests performed by SwRI on the cesium-loaded SRF resin. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. The as-received SwRI report is attached to this report in the Appendix A. Where applicable, the precision and bias of each test method, as given by each American Society for Testing and Materials (ASTM) standard procedure, are included and compared with the SwRI test results of the cesium-loaded SRF resin.« less

Cold-Atom Clocks on Earth and in Space

NASA Astrophysics Data System (ADS)

Lemonde, Pierre; Laurent, Philippe; Santarelli, Giorgio; Abgrall, Michel; Sortais, Yvan; Bize, Sebastien; Nicolas, Christophe; Zhang, Shougang; Clairon, Andre; Dimarcq, Noel; Petit, Pierre; Mann, Antony G.; Luiten, Andre N.; Chang, Sheng; Salomon, Christophe

We present recent progress on microwave clocks that make use of laser-cooled atoms. With an ultra-stable cryogenic sapphire oscillator as interrogation oscillator, a cesium fountain operates at the quantum projection noise limit. With 6 x10^5 detected atoms, the relative frequency stability is 4 x10^-14 &1/2circ, where τ is the integration time in seconds. This stability is comparable to that of hydrogen masers. At τ=2 x10^4s, the measured stability reaches 6 x10^-16. A 87Rb fountain has also been constructed and the 87Rb ground-state hyperfine energy has been compared to the Cs primary standard with a relative accuracy of 2.5 x10^-15. The 87Rb collisional shift is found to be at least 30 times below that of cesium. We also describe a transportable cesium fountain, which will be used for frequency comparisons with an accuracy of 10-15 or below. Finally, we present the details of a space mission for a cesium standard which has been selected by the European Space Agency (ESA) to fly on the International Space Station in 2003.

Cellulose nanofiber backboned Prussian blue nanoparticles as powerful adsorbents for the selective elimination of radioactive cesium.

PubMed

Vipin, Adavan Kiliyankil; Fugetsu, Bunshi; Sakata, Ichiro; Isogai, Akira; Endo, Morinobu; Li, Mingda; Dresselhaus, Mildred S

2016-11-15

On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi's damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (10 6 ) order of magnitude distribution coefficient (K d ) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications.

Radioactive cesium isotope ratios as a tool for determining dispersal and re-dispersal mechanisms downwind from the Nevada Nuclear Security Site.

PubMed

Snyder, Darin C; Delmore, James E; Tranter, Troy; Mann, Nick R; Abbott, Michael L; Olson, John E

2012-08-01

Fractionation of the two longer-lived radioactive cesium isotopes ((135)Cs and (137)Cs) produced by above ground nuclear tests have been measured and used to clarify the dispersal mechanisms of cesium deposited in the area between the Nevada Nuclear Security Site and Lake Mead in the southwestern United States. Fractionation of these isotopes is due to the 135-decay chain requiring several days to completely decay to (135)Cs, and the 137-decay chain less than one hour decay to (137)Cs. Since the Cs precursors are gases, iodine and xenon, the (135)Cs plume was deposited farther downwind than the (137)Cs plume. Sediment core samples were obtained from the Las Vegas arm of Lake Mead, sub-sampled and analyzed for (135)Cs/(137)Cs ratios by thermal ionization mass spectrometry. The layers proved to have nearly identical highly fractionated isotope ratios. This information is consistent with a model where the cesium was initially deposited onto the land area draining into Lake Mead and the composite from all of the above ground shots subsequently washed onto Lake Mead by high intensity rain and wind storms producing a layering of Cs activity, where each layer is a portion of the composite. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cellulose nanofiber backboned Prussian blue nanoparticles as powerful adsorbents for the selective elimination of radioactive cesium

PubMed Central

Vipin, Adavan Kiliyankil; Fugetsu, Bunshi; Sakata, Ichiro; Isogai, Akira; Endo, Morinobu; Li, Mingda; Dresselhaus, Mildred S.

2016-01-01

On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi’s damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (106) order of magnitude distribution coefficient (Kd) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications. PMID:27845441

Cesium radioactivity in peripheral blood is linearly correlated to that in skeletal muscle: analyses of cattle within the evacuation zone of the Fukushima Daiichi Nuclear Power Plant.

PubMed

Fukuda, Tomokazu; Kino, Yasushi; Abe, Yasuyuki; Yamashiro, Hideaki; Kobayashi, Jin; Shimizu, Yoshinaka; Takahashi, Atsushi; Suzuki, Toshihiko; Chiba, Mirei; Takahashi, Shintaro; Inoue, Kazuya; Kuwahara, Yoshikazu; Morimoto, Motoko; Shinoda, Hisashi; Hiji, Masahiro; Sekine, Tsutomu; Fukumoto, Manabu; Isogai, Emiko

2015-01-01

The accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) released a large amount of radioactive substances into the environment. Furthermore, beef contaminated with radioactive cesium above the 500 Bq/kg safety standard was circulated in the food chain in 2011. Japanese consumers remain concerned about the safety of radioactively contaminated food. In our previous study, we detected a linear correlation between radioactive cesium ((137) Cs) activity in blood and muscle around 500 to 2500 Bq/kg in cattle. However, it was unclear whether the correlation was maintained at a lower radioactivity close to the current safety standard of 100 Bq/kg. In this study, we evaluated 17 cattle in the FNPP evacuation zone that had a (137) Cs blood level less than 10 Bq/kg. The results showed a linear correlation between blood (137) Cs and muscle (137) Cs (Y = 28.0X, R(2)  = 0.590) at low radioactivity concentration, indicating that cesium radioactivity in the muscle can be estimated from blood radioactivity. This technique would be useful in detecting high-risk cattle before they enter the market, and will contribute to food safety. © 2014 Japanese Society of Animal Science.

Uptake and transport of radioactive cesium and strontium into grapevines after leaf contamination

NASA Astrophysics Data System (ADS)

Zehnder, H. J.; Kopp, P.; Eikenberg, J.; Feller, U.; Oertli, J. J.

1995-07-01

From 1989 to 1993 the foliar uptake of radioactive strontium (Sr-85) and cesium (Cs-134) by selected leaves of grapevine plants and the subsequent redistribution within the plants was examined under controlled conditions in a greenhouse. The radionuclides were applied as chlorides. These plants were grown in large pots containing a mixture of local soil and peat. Plant and soil samples were analyzed throughout the growing season and also during the following vegetation period. Only traces of the applied radiostrontium were taken up by the leaves. This element was essentially not redistributed within the plants. In contrast, radiocesium was easily taken up through the leaf surface, transported to other plant parts and to some extent released from the roots into the soil. Cesium reaching the soil may interact with clay particles causing a very reduced availability for plants. Therefore the soil may act as a long-term sink for radiocesium. On the other hand, grape berries represent transient sinks. The cesium levels in the berries decreased again in a late phase of maturation, but the mechanisms causing this loss are not yet identified. During the second vegetation period, only a very minor proportion of the radiocesium taken up previously by the plants was present in the above ground parts.

Microtomography-based Inter-Granular Network for the simulation of radionuclide diffusion and sorption in a granitic rock

NASA Astrophysics Data System (ADS)

Iraola, Aitor; Trinchero, Paolo; Voutilainen, Mikko; Gylling, Björn; Selroos, Jan-Olof; Molinero, Jorge; Svensson, Urban; Bosbach, Dirk; Deissmann, Guido

2017-12-01

Field investigation studies, conducted in the context of safety analyses of deep geological repositories for nuclear waste, have pointed out that in fractured crystalline rocks sorbing radionuclides can diffuse surprisingly long distances deep into the intact rock matrix; i.e. much longer distances than those predicted by reactive transport models based on a homogeneous description of the properties of the rock matrix. Here, we focus on cesium diffusion and use detailed micro characterisation data, based on micro computed tomography, along with a grain-scale Inter-Granular Network model, to offer a plausible explanation for the anomalously long cesium penetration profiles observed in these in-situ experiments. The sparse distribution of chemically reactive grains (i.e. grains belonging to sorbing mineral phases) is shown to have a strong control on the diffusive patterns of sorbing radionuclides. The computed penetration profiles of cesium agree well with an analytical model based on two parallel diffusive pathways. This agreement, along with visual inspection of the spatial distribution of cesium concentration, indicates that for sorbing radionuclides the medium indeed behaves as a composite system, with most of the mass being retained close to the injection boundary and a non-negligible part diffusing faster along preferential diffusive pathways.

40 CFR Appendix A to Subpart I of... - Alternative Procedures for Measuring Point-of-Use Abatement Device Destruction or Removal Efficiency

Code of Federal Regulations, 2014 CFR

2014-07-01

... native AOI concentration (ppm) of the effluent during stable conditions. (14) Post-test calibration. At... or removal efficiencies must be determined while etching a substrate (product, dummy, or test). For... curves for the subsequent destruction or removal efficiency tests. (8) Mass location calibration. A...

H- Ion Sources for High Intensity Proton Drivers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Rolland Paul; Dudnikov, Vadim

2015-02-20

Existing RF Surface Plasma Sources (SPS) for accelerators have specific efficiencies for H + and H - ion generation around 3 to 5 mA/cm 2 per kW, where about 50 kW of RF power is typically needed for 50 mA beam current production. The Saddle Antenna (SA) SPS described here was developed to improve H- ion production efficiency, reliability and availability for pulsed operation as used in the ORNL Spallation Neutron Source . At low RF power, the efficiency of positive ion generation in the plasma has been improved to 200 mA/cm 2 per kW of RF power at 13.56more » MHz. Initial cesiation of the SPS was performed by heating cesium chromate cartridges by discharge as was done in the very first versions of the SPS. A small oven to decompose cesium compounds and alloys was developed and tested. After cesiation, the current of negative ions to the collector was increased from 1 mA to 10 mA with RF power 1.5 kW in the plasma (6 mm diameter emission aperture) and up to 30 mA with 4 kW RF power in the plasma and 250 Gauss longitudinal magnetic field. The ratio of electron current to negative ion current was improved from 30 to 2. Stable generation of H- beam without intensity degradation was demonstrated in the aluminum nitride (AlN) discharge chamber for 32 days at high discharge power in an RF SPS with an external antenna. Some modifications were made to improve the cooling and cesiation stability. The extracted collector current can be increased significantly by optimizing the longitudinal magnetic field in the discharge chamber. While this project demonstrated the advantages of the pulsed version of the SA RF SPS as an upgrade to the ORNL Spallation Neutron Source, it led to a possibility for upgrades to CW machines like the many cyclotrons used for commercial applications. Four appendices contain important details of the work carried out under this grant.« less

Mastication and oral health-related quality of life in removable denture wearers with Alzheimer disease.

PubMed

Campos, Camila H; Ribeiro, Giselle R; Rodrigues Garcia, Renata C M

2018-05-01

Alzheimer disease (AD) can affect masticatory function, affecting oral health-related quality of life (OHRQoL). Whether oral rehabilitation with conventional removable prostheses can restore masticatory function and improve OHRQoL in these individuals is unknown. The purpose of this clinical study was to evaluate the influence of oral rehabilitation with removable prostheses on masticatory efficiency and OHRQoL in elders with and without AD. Thirty-two elders with mild AD (n=16, mean age=76.7 ±6.3 years) or without AD (n=16, mean age=75.2 ±4.4 years) were recruited. All participants first underwent masticatory efficiency and OHRQoL evaluations, and 2 months after insertion of new removable prostheses, the variables were reassessed. Masticatory efficiency was determined using the sieving method, and OHRQoL was measured by applying the Geriatric Oral Health Assessment Index (GOHAI). The data from the baseline and after insertion of the new removable prostheses were compared by paired t test. Group differences at each time point were assessed by t test (α=.05). After insertion of the new removable prostheses, masticatory efficiency and OHRQoL improved in both the elders with AD and the control. At baseline, elders with AD had lower masticatory efficiency and higher OHRQoL than controls (P<.05). After removable prosthesis insertion, elders with AD continued to show lower masticatory efficiency values than controls, but their OHRQoL was similar. Oral rehabilitation with new removable prostheses improved the masticatory efficiency and OHRQoL of elders with and without AD, although masticatory efficiency did not reach control levels in elders with AD. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Removal of pharmaceuticals from wastewater by biological processes, hydrodynamic cavitation and UV treatment.

PubMed

Zupanc, Mojca; Kosjek, Tina; Petkovšek, Martin; Dular, Matevž; Kompare, Boris; Širok, Brane; Blažeka, Željko; Heath, Ester

2013-07-01

To augment the removal of pharmaceuticals different conventional and alternative wastewater treatment processes and their combinations were investigated. We tested the efficiency of (1) two distinct laboratory scale biological processes: suspended activated sludge and attached-growth biomass, (2) a combined hydrodynamic cavitation-hydrogen peroxide process and (3) UV treatment. Five pharmaceuticals were chosen including ibuprofen, naproxen, ketoprofen, carbamazepine and diclofenac, and an active metabolite of the lipid regulating agent clofibric acid. Biological treatment efficiency was evaluated using lab-scale suspended activated sludge and moving bed biofilm flow-through reactors, which were operated under identical conditions in respect to hydraulic retention time, working volume, concentration of added pharmaceuticals and synthetic wastewater composition. The suspended activated sludge process showed poor and inconsistent removal of clofibric acid, carbamazepine and diclofenac, while ibuprofen, naproxen and ketoprofen yielded over 74% removal. Moving bed biofilm reactors were filled with two different types of carriers i.e. Kaldnes K1 and Mutag BioChip™ and resulted in higher removal efficiencies for ibuprofen and diclofenac. Augmentation and consistency in the removal of diclofenac were observed in reactors using Mutag BioChip™ carriers (85%±10%) compared to reactors using Kaldnes carriers and suspended activated sludge (74%±22% and 48%±19%, respectively). To enhance the removal of pharmaceuticals hydrodynamic cavitation with hydrogen peroxide process was evaluated and optimal conditions for removal were established regarding the duration of cavitation, amount of added hydrogen peroxide and initial pressure, all of which influence the efficiency of the process. Optimal parameters resulted in removal efficiencies between 3-70%. Coupling the attached-growth biomass biological treatment, hydrodynamic cavitation/hydrogen peroxide process and UV treatment resulted in removal efficiencies of >90% for clofibric acid and >98% for carbamazepine and diclofenac, while the remaining compounds were reduced to levels below the LOD. For ibuprofen, naproxen, ketoprofen and diclofenac the highest contribution to overall removal was attributed to biological treatment, for clofibric acid UV treatment was the most efficient, while for carbamazepine hydrodynamic cavitation/hydrogen peroxide process and UV treatment were equally efficient. Copyright © 2012 Elsevier B.V. All rights reserved.

Mineral-deposit model for lithium-cesium-tantalum pegmatites

USGS Publications Warehouse

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 derived by fractional crystallization. In cases where a parental granite pluton is not exposed, one is inferred to lie at depth. Lithium-cesium-tantalum LCT pegmatite melts are enriched in fluxing components including H2O, F, P, and B, which depress the solidus temperature, lower the density, and increase rates of ionic diffusion. This, in turn, enables pegmatites to form thin dikes and massive crystals despite having a felsic composition and temperatures that are significantly lower than ordinary granitic melts. Lithium-cesium-tantalum pegmatites crystallized at remarkably low temperatures (about 350–550 °C) in a remarkably short time (days to years).Lithium-cesium-tantalum pegmatites form in orogenic hinterlands as products of plate convergence. Most formed during collisional orogeny (for example, Kings Mountain district, North Carolina). Specific causes of LCT pegmatite-related magmatism could include: ordinary arc processes; over thickening of continental crust during collision or subduction; slab breakoff during or after collision; slab delamination before, during, or after collision; and late collisional extensional collapse and consequent decompression melting. Lithium-cesium-tantalum pegmatite deposits are present in all continents including Antarctica and in rocks spanning 3 billion years of Earth history. The global age distribution of LCT pegmatites is similar to those of common pegmatites, orogenic granites, and detrital zircons. Peak times of LCT pegmatite genesis at about 2640, 1800, 960, 485, and 310 Ma (million years before present) correspond to times of collisional orogeny and supercontinent assembly. Between these pulses were long intervals when few or no LCT pegmatites formed. These minima overlap with supercontinent tenures at ca. 2450–2225, 1625–1000, 875–725, and 250–200 Ma.Exploration and assessment for LCT pegmatites are guided by a number of observations. In frontier areas where exploration has been minimal at best, the key first-order criteria are an orogenic hinterland setting, appropriate regional metamorphic grades, and the presence of evolved granites and common granitic pegmatites. New LCT pegmatites are most likely to be found near known deposits. Pegmatites tend to show a regional mineralogical and geochemical zoning pattern with respect to the inferred parental granite, with the greatest enrichment in the more distal pegmatites. Mineral-chemical trends in common pegmatites that can point toward an evolved LCT pegmatite include: increasing rubidium in potassium feldspar, increasing lithium in white mica, increasing manganese in garnet, and increasing tantalum and manganese in columbite-tantalite. Most LCT pegmatite bodies show a distinctive internal zonation featuring four zones: border, wall, intermediate (where lithium, cesium, and tantalum are generally concentrated), and core. This zonation is expressed both in cross section and map view; thus, what may appear to be a common pegmatite may instead be the edge of a mineralized body.Neither lithium-cesium-tantalum pegmatites nor their parental granites are likely to cause serious environmental concerns. Soils and country rock surrounding a LCT pegmatite, as well as waste from mining operations, may be enriched in characteristic elements relative to global average soil and bedrock values. These elements may include lithium, cesium, tantalum, beryllium, boron, fluorine, phosphorus, manganese, gallium, rubidium, niobium, tin, and hafnium. Among this suite of elements, however, the only ones that might present a concern for environmental health are beryllium and fluorine, which are included in the U.S. Environmental Protection Agency drinking-water regulations with maximum contaminant levels of 4 micrograms per liter and 4 milligrams per liter, respectively.

Spray scrubbing of particulate-laden SO(2) using a critical flow atomizer.

PubMed

Bandyopadhyay, Amitava; Biswas, Manindra Nath

2008-08-01

The performance of a spray tower using an energy efficient two-phase critical flow atomizer on the scrubbing of particulate-laden SO(2) using water and dilute NaOH is reported in this article. Experimentation revealed that SO(2) removal was enhanced due to presence of particles (fly-ash) and almost 100% removal efficiency was achieved in water scrubbing. The removal efficiency is elucidated in reference to atomizing air pressure, droplet diameter and droplet velocity besides other pertinent variables of the system studied. The presence of fly-ash particles improved the removal efficiency to about 20% within the range of variables studied. Empirical and semi-empirical correlations were developed for predicting the removal efficiency in water and dilute NaOH respectively. Predicted data fitted excellently well with experimental values. The performance of the spray tower is compared with the performances of existing systems and very encouraging results are obtained.

[Efficiency of photodecomposition of trace NDMA in water by UV irradiation].

PubMed

Xu, Bing-Bing; Chen, Zhong-Lin; Qi, Fei; Ma, Jun

2008-07-01

Efficiency of photodecomposition of trace NDMA by UV irradiation was investigated with analyzing the initial concentration of NDMA, solution pH, irradiation area, irradiation intensity and water quality effect on NDMA photolysis. NDMA could be effectively photodegraded by UV irradiation. The removal efficiency of NDMA was 97.5% after 5 min of UV irradiation. Effect of initial NDMA concentration on photodecomposition of NDMA was not remarkable. With pH value ascending, the removal rate of NDMA photodecomposition decreased. The yields of photoquantum were more under lower solution pH than that under higher pH. NDMA had fastest reaction rate at solution pH = 2.2. Removal efficiency of NDMA increased with the available irradiation area ascending. Increscent ultraviolet irradiation intensity was good for NDMA degradation. Water quality affected the removal of NDMA slightly. The removal efficiency of NDMA in tap water and Songhua River raw water were 96.7% and 94.8%, respectively.

Treatment of emulsified oils by electrocoagulation: pulsed voltage applications.

PubMed

Genc, Ayten; Bakirci, Busra

2015-01-01

The effect of pulsed voltage application on energy consumption during electrocoagulation was investigated. Three voltage profiles having the same arithmetic average with respect to time were applied to the electrodes. The specific energy consumption for these profiles were evaluated and analyzed together with oil removal efficiencies. The effects of applied voltages, electrode materials, electrode configurations, and pH on oil removal efficiency were determined. Electrocoagulation experiments were performed by using synthetic and real wastewater samples. The pulsed voltages saved energy during the electrocoagulation process. In continuous operation, energy saving was as high as 48%. Aluminum electrodes used for the treatment of emulsified oils resulted in higher oil removal efficiencies in comparison with stainless steel and iron electrodes. When the electrodes gap was less than 1 cm, higher oil removal efficiencies were obtained. The highest oil removal efficiencies were 95% and 35% for the batch and continuous operating modes, respectively.

Comparison of the removal of ethanethiol in twin-biotrickling filters inoculated with strain RG-1 and B350 mixed microorganisms.

PubMed

An, Taicheng; Wan, Shungang; Li, Guiying; Sun, Lei; Guo, Bin

2010-11-15

This study aims to compare the biological degradation performance of ethanethiol using strain RG-1 and B350 commercial mixed microorganisms, which were inoculated and immobilized on ceramic particles in twin-biotrickling filter columns. The parameters affecting the removal efficiency, such as empty bed residence time (EBRT) and inlet concentration, were investigated in detail. When EBRT ranged from 332 to 66 s at a fixed inlet concentration of 1.05 mg L(-1), the total removal efficiencies for RG-1 and B350 both decreased from 100% to 70.90% and 47.20%, respectively. The maximum elimination capacities for RG-1 and B350 were 38.36 (removal efficiency=89.20%) and 25.82 g m(-3) h(-1) (removal efficiency=57.10%), respectively, at an EBRT of 83 s. The variation of the inlet concentration at a fixed EBRT of 110 s did not change the removal efficiencies which remained at 100% for RG-1 and B350 at concentrations of less than 1.05 and 0.64 mg L(-1), respectively. The maximum elimination capacities were 39.93 (removal efficiency=60.30%) and 30.34 g m(-3) h(-1) (removal efficiency=46.20%) for RG-1 and B350, respectively, at an inlet concentration of 2.03 mg L(-1). Sulfate was the main metabolic product of sulfur in ethanethiol. Based the results, strain RG-1 would be a better choice than strain B350 for the biodegradation of ethanethiol. Copyright © 2010 Elsevier B.V. All rights reserved.

Simultaneous removal of aniline, nitrogen and phosphorus in aniline-containing wastewater treatment by using sequencing batch reactor.

PubMed

Jiang, Yu; Wang, Hongyu; Shang, Yu; Yang, Kai

2016-05-01

The high removal efficiencies of traditional biological aniline-degrading systems always lead to accumulation of ammonium. In this study, simultaneous removal of aniline, nitrogen and phosphorus in a single sequencing batch reactor was achieved by using anaerobic/aerobic/anoxic (A/O/A) operational process. The removal efficiencies of COD, NH4(+)-N, TN, TP were over 95.80%, 83.03%, 87.13%, 90.95%, respectively in most cases with 250mgL(-1) of initial aniline at 6h cycle when DO was 5.5±0.5mgL(-1). Aniline was able to be completely degraded when initial concentrations were less than 750mgL(-1). When DO increased, the removal rate of NH4(+)-N and TP slightly increased along with the moderate decrease of removal efficiencies of TN. The variation of HRT had obvious influence on removal performance of pollutants. The system showed high removal efficiencies of aniline, COD and nutrients during the variation of operating conditions, which might contribute to disposal of aniline-rich industrial wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of dissolved organic matter concentration and composition on the removal efficiency of perfluoroalkyl substances (PFASs) during drinking water treatment.

PubMed

Kothawala, Dolly N; Köhler, Stephan J; Östlund, Anna; Wiberg, Karin; Ahrens, Lutz

2017-09-15

Drinking water treatment plants (DWTPs) are constantly adapting to a host of emerging threats including the removal of micro-pollutants like perfluoroalkyl substances (PFASs), while concurrently considering how background levels of dissolved organic matter (DOM) influences their removal efficiency. Two adsorbents, namely anion exchange (AE) and granulated active carbon (GAC) have shown particular promise for PFAS removal, yet the influence of background levels of DOM remains poorly explored. Here we considered how the removal efficiency of 13 PFASs are influenced by two contrasting types of DOM at four concentrations, using both AE (Purolite A-600 ® ) and GAC (Filtrasorb 400 ® ). We placed emphasis on the pre-equilibrium conditions to gain better mechanistic insight into the dynamics between DOM, PFASs and adsorbents. We found AE to be very effective at removing both PFASs and DOM, while largely remaining resistant to even high levels of background DOM (8 mg carbon L -1 ) and surprisingly found that smaller PFASs were removed slightly more efficiently than longer chained counterparts, In contrast, PFAS removal efficiency with GAC was highly variable with PFAS chain length, often improving in the presence of DOM, but with variable response based on the type of DOM and PFAS chain length. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of influent aeration on removal of organic matter from coffee processing wastewater in constructed wetlands.

PubMed

Rossmann, Maike; Matos, Antonio Teixeira; Abreu, Edgar Carneiro; Silva, Fabyano Fonseca; Borges, Alisson Carraro

2013-10-15

The aim of the present study was to evaluate the influence of aeration and vegetation on the removal of organic matter in coffee processing wastewater (CPW) treated in 4 constructed wetlands (CWs), characterized as follows: (i) ryegrass (Lolium multiflorum) cultivated system operating with an aerated influent; (ii) non-cultivated system operating with an aerated influent, (iii) ryegrass cultivated system operating with a non-aerated influent; and (iv) non-cultivated system operating with a non-aerated influent. The lowest average chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) removal efficiencies of 87, 84 and 73%, respectively, were obtained in the ryegrass cultivated system operating with a non-aerated influent. However, ryegrass cultivation did not influence the removal efficiency of organic matter. Artificial aeration of the CPW, prior to its injection in the CW, did not improve the removal efficiencies of organic matter. On other hand it did contribute to increase the instantaneous rate at which the maximum COD removal efficiency was reached. Although aeration did not result in greater organic matter removal efficiencies, it is important to consider the benefits of aeration on the removal of the other compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effective adsorption and collection of cesium from aqueous solution using graphene oxide grown on porous alumina

NASA Astrophysics Data System (ADS)

Entani, Shiro; Honda, Mitsunori; Shimoyama, Iwao; Li, Songtian; Naramoto, Hiroshi; Yaita, Tsuyoshi; Sakai, Seiji

2018-04-01

Graphene oxide (GO) with a large surface area was synthesized by the direct growth of GO on porous alumina using chemical vapor deposition to study the Cs adsorption mechanism in aqueous solutions. Electronic structure analysis employing in situ near-edge X-ray absorption fine structure spectroscopy and X-ray photoelectron spectroscopy measurements clarifies the Cs atoms bond via oxygen functional groups on GO in the aqueous solution. The Cs adsorption capacity was found to be as high as 650-850 mg g-1, which indicates that the GO/porous alumina acts as an effective adsorbent with high adsorption efficiency for radioactive nuclides in aqueous solutions.

Resonance Ionization Mass Spectrometry System for Measurement of Environmental Samples

NASA Astrophysics Data System (ADS)

Pibida, L.; McMahon, C. A.; Nörtershäuser, W.; Bushaw, B. A.

2002-10-01

A resonance ionization mass spectrometry (RIMS) system has been developed at the National Institute of Standards and Technology (NIST) for sensitive and selective determination of radio-cesium in the environment. The overall efficiency was determined to be 4×10-7 with a combined (laser and mass spectrometer) selectivity of 108 for both 135Cs and 137Cs with respect to 133Cs. RIMS isotopic ratio measurements of 135Cs/ 137Cs were performed on a nuclear fuel burn-up sample and compared to measurements on a similar system at Pacific Northwest National Laboratory (PNNL) and to conventional thermal ionization mass spectrometry (TIMS). Results of preliminary RIMS investigations on a freshwater lake sediment sample are also discussed.

Radiation energy conversion in space; Conference, 3rd, NASA Ames Research Center, Moffett Field, Calif., January 26-28, 1978, Technical Papers

NASA Technical Reports Server (NTRS)

Billman, K. W.

1978-01-01

Concepts for space-based conversion of space radiation energy into useful energy for man's needs are developed and supported by studies of costs, material and size requirements, efficiency, and available technology. Besides the more studied solar power satellite system using microwave transmission, a number of alternative space energy concepts are considered. Topics covered include orbiting mirrors for terrestrial energy supply, energy conversion at a lunar polar site, ultralightweight structures for space power, radiatively sustained cesium plasmas for solar electric conversion, solar pumped CW CO2 laser, superelastic laser energy conversion, laser-enhanced dynamics in molecular rate processes, and electron beams in space for energy storage.

Decontamination work in the area surrounding Fukushima Dai-ichi Nuclear Power Plant: another occupational health challenge of the nuclear disaster.

PubMed

Wada, Koji; Yoshikawa, Toru; Murata, Masaru

2012-01-01

This article describes occupational health measures for workers involved in decontamination of radioactive material discharged around Fukushima Dai-ichi Nuclear Power Plant after the explosions in 2011. Decontamination is performed by removing radioactive particles (mainly cesium) from surfaces of soil, grass and trees, and buildings. Measurement of radiation doses is necessary to reduce exposure, and to determine whether workers can work below dose limits. Protective equipment for decontamination is determined based on the concentration of radiation in contaminated soil and the exposure to dust. Health examinations by physicians are mandated for decontamination workers upon hiring and every 6 months. While there is no possibility of acute radiation injury from decontamination, workers may be anxious about the unclear effects of chronic low level radiation exposure on health. Measures to protect the decontamination workers are the top priority.

Final Project Report: Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jon Chorover, University of Arizona; Peggy O'€™Day, University of California, Merced; Karl Mueller, Penn State University

2012-10-01

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake. In this project, we studied the impact of background pore water (BPW) on strontium, cesium and iodine desorption and transport in Hanford sediments that were experimentally weathered by contact with simulated hyperalkaline tank waste leachate (STWL) solutions. Using those lab-weathered Hanford sediments (HS) and model precipitates formed during nucleation from homogeneous STWL solutions (HN), we (i) provided detailed characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, PCO2, and reaction time; (ii) improved molecular-scale understanding of howmore » sorbate speciation controls contaminant desorption from weathered sediments upon removal of caustic sources; and (iii) developed a mechanistic, predictive model of meso- to field-scale contaminant reactive transport under these conditions.« less

Determination of low (137)Cs concentration in seawater using ammonium 12-molybdophosphate adsorption and chemical separation method.

PubMed

Park, J H; Chang, B U; Kim, Y J; Seo, J S; Choi, S W; Yun, J Y

2008-12-01

A new method has been developed for analyzing (137)Cs in a small volume of seawater. Ammonium 12-molybdophosphate (AMP) was used two times during pretreatment procedure. The first step was to adsorb (137)Cs in seawater samples into AMP in order to reduce sample volume, and the second was to remove (87)Rb, interference nuclide for beta counting. The AMP adsorbing (137)Cs was dissolved by sodium hydroxide solution, and then (137)Cs was finally formed to be cesium chloroplatinate precipitate by adding 10% hexachloroplatinic acid. The beta rays emitted from (137)Cs were measured with a low background gas-proportional alpha/beta counter. This method was applied to several seawater samples taken in the East Sea of Korea. Compared to the routinely used gamma-spectrometry method, this new AMP method was reliable and suitable for analyzing (137)Cs in deep seawater.

Fate of estrogens in a pilot-scale step-feed anoxic/oxic wastewater treatment system controlling by nitrogen and phosphorus removal.

PubMed

Chen, Qingcai; Li, Zebing; Hua, Xiaoyu

2018-05-01

The control measures for estrogens in the aquatic environment are topics of growing concern. It is a meaningful issue to finding optimal process parameters for efficient removal of estrogens with the purpose of efficient total nitrogen (TN) or total phosphorus (TP) removal in sewage treatment plants. The present paper is concerned with the relationships between the estrogen removal and TN or TP removal in a pilot-scale three-stage anoxic/oxic (A/O) system treating real municipal wastewater. The total removal efficiency for estrone (E1) and 17β-estradiol (E2) and their sulfate and glucuronide conjugates were on average 87% in the pilot-scale system. The concentrations of the sulfate and glucuronide conjugates of estrogens (E1 and E2) in the system were much lower than the estrogens, which might be caused by the rapid degradation of conjugates in the pilot-scale system. The average removal efficiencies of E1 and E2 and their sulfate and glucuronide conjugates were significantly lower under high TP removal conditions than those under high TN removal conditions that suggested that the ammonia oxidation promotes estrogen degradation. When the system achieved efficient TN removal, the concentrations of both E1 and E2 were generally lower in the aerobic zones than those in the anoxic zones. Instead, when the system achieved efficient TP removal conditions, the estrogen concentrations were higher in the aerobic zones than in the anoxic zones. However, it was thought that the variation of the concentrations of the estrogen conjugates had weak influence on concentrations of the free estrogens. The increase of the free estrogens in the aerobic zones could be attributed to the release of the estrogens adsorbed on the sludge. The variation of estrogens in a three-stage A/O system can be properly estimated and measured by a binary linear regression model with the variables of TP and TON (NO 2 - -N and NO 3 - -N), which is probably the important information for the improvement and optimization of wastewater treatment processes to obtain higher removal efficiency for estrogens.

A testing-coverage software reliability model considering fault removal efficiency and error generation

PubMed Central

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance. PMID:28750091

Phosphorous removal from aqueous solution can be enhanced through the calcination of lime sludge.

PubMed

Bal Krishna, K C; Niaz, Mohamed R; Sarker, Dipok C; Jansen, Troy

2017-09-15

Water treatment plants generate an enormous amount of the sludge which is normally treated as waste. In the recent past, many investigations have been focused on developing an economical adsorbent using water treatment sludge to remove phosphorous (P) from aqueous solutions. However, the great extents of the studies have been limited in the use of alum- and iron-based sludges. This study, therefore, investigated the P removal performance of the calcined lime sludge. Calcined lime sludge at 700 °C significantly enhanced the P removal efficiency whereas marginal improvement was noted when the sludge calcined at 400 °C was tested. With increase P removal efficiency, final pH values of the solution also significantly increased. P removal efficiency of the calcined sludge decreased with increasing the initial P concentrations. However, the removal efficiency could be improved by increasing the weight of the sludge. Further analysis demonstrated that P removal trend followed both pseudo-second order and diffusion-chemisorption kinetics signifying the P removal is potentially due to a multi-mechanistic reaction in which, the process is controlled by intra-particle diffusion followed by chemisorptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

USSR Report, Life Sciences Biomedical and Behavioral Sciences

DTIC Science & Technology

1984-02-15

G. P. Somov; ZHURNAL MIKROBIOLOGII, EPIDEMIOLOGII I IMMUNOBIOLOGII, No 10, Oct 83) 12 Modern Preventive Measures for Zoonotic Infections (V. P...However, the concentrations of strontium-90 and cesium- 137 in the milk , potatoes and vegetables remained virtually unchanged in the period...covered, with the cesium-137/strontium-90 ratio ranging from 0.45 (carrots) to 2.75 ( milk ) in 1980, and from 0.55 (beets) to 4.0 ( milk ) in 1981. [130

Design and operation of a 1000 C lithium-cesium test system

NASA Technical Reports Server (NTRS)

Hays, L. G.; Haskins, G. M.; Oconnor, D. E.; Torola, J., Jr.

1973-01-01

A 100 kWt cesium-lithium test loop fabricated of niobium-1% zirconium for experiments on erosion and two-phase system operation at temperatures of 980 C and velocities of 150 m/s. Although operated at design temperature for 100 hours, flow instabilities in the two-phase separator interfered with the achievement of the desired mass flow rates. A modified separator was fabricated and installed in the loop to alleviate this problem.

Off-Site Monitoring of Nuclear Fuel Reprocessing Plants for Nuclear Weapons Proliferation

DTIC Science & Technology

1980-01-01

of commercial nuclear power reactors by the collection of cesium and neodynium radionuclides and the use-of isotopic correlation techniques.Both...Both Goodwin (ref 1) and Clark (ref 2) investigated off-site monitoring of commercial nuclear power reactoze by the collection of cesium and neodynium...manner than that which is used for power production.Economical generation of electrical power requires a long sus- tained fission cycle whereas Pu-239

Radioactive pollution of the waters of the baltic sea during 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarev, L.N.; Kuznetsov, Yu.V.; Gedeonov, L.I.

Results are presented from an investigation of radioactive pollution of the waters of the Baltic Sea during 1986. Inhomogeneities in the pollution of this area of water, due to varying density of atmospheric radioactive fallout, are detected. It is found that among the radionuclides entering the surface of the Baltic Sea in 1986 as a result of atmospheric transport, the main one in terms of radiation dose is cesium-137. Comparisons are made of the level of cesium-137 content in the waters of the Baltic Sea in 1986 and in preceding years. It is noted that even in the most pollutedmore » regions of the sea the cesium-137 content was 500 times less than the maximum allowable concentration (MAC) in the USSR for drinking water. The first results of the determination of plutonium-239 and 240 in the Baltic Sea are presented.« less

Modeling of a diode-pumped thin-disk cesium vapor laser

NASA Astrophysics Data System (ADS)

An, Guofei; Cai, He; Liu, Xiaoxu; Han, Juhong; Zhang, Wei; Wang, Hongyuan; Wang, You

2018-03-01

A diode pumped alkali laser (DPAL) provides a significant potential for construction of high-powered lasers. Until now, a series of models have been established to analyze the kinetic process and most of them are based on the end-pumped alkali laser system in which the vapor cell are usually cylindrical and cuboid. In this paper, a mathematic model is constructed to investigate the kinetic processes of a diode pumped thin-disk cesium vapor laser, in which the cesium vapor and the buffer gases are beforehand filled in a sealed glass cell with a thin-disk structure. We systemically study the influences of the cell temperature and cell thickness on the output features of a thin-disk DPAL. Further, we study the thin-disk DPAL with the W-shaped resonator and multiple-disk configuration. To the best of our knowledge, there have not been any similar reports so far.

Multiple delivery cesium oven system for negative ion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, G.; Bhartiya, S.; Pandya, K.

2012-02-15

Distribution of cesium in large negative ion beam sources to be operational in ITER, is presently based on the use of three or more cesium ovens, which operate simultaneously and are controlled remotely. However, use of multiple Cs ovens simultaneously is likely to pose difficulties in operation and maintenance of the ovens. An alternate method of Cs delivery, based on a single oven distribution system is proposed as one which could reduce the need of simultaneous operation of many ovens. A proof of principle experiment verifying the concept of a multinozzle distributor based Cs oven has been carried out atmore » Institute for Plasma Research. It is also observed that the Cs flux is not controlled by Cs reservoir temperature after few hours of operation but by the temperature of the distributor which starts behaving as a Cs reservoir.« less

Extraction, scrub, and strip test results for the solvent transfer to salt waste processing facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T.

The Savannah River National Laboratory (SRNL) prepared approximately 240 gallons of Caustic-Side Solvent Extraction (CSSX) solvent for use at the Salt Waste Processing Facility (SWPF). An Extraction, Scrub, and Strip (ESS) test was performed on a sample of the prepared solvent using a salt solution prepared by Parsons to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams. This data will be used by Parsons to help qualify the solvent for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations.more » The extraction D(Cs) measured 15.5, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.« less

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

PubMed Central

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

2015-01-01

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. PMID:25740624

An ab initio cluster study of the chemisorption of atomic cesium and hydrogen on reconstructed surfaces of gallium rich gallium arsenide

NASA Astrophysics Data System (ADS)

Schailey, Ronald

1999-11-01

Chemisorption properties of cesium and hydrogen atoms on the Ga-rich GaAs (100) (2 x 1), (2 x 2), and β(4 x 2) surfaces are investigated using ab initio self-consistent restricted open shell Hartree-Fock (ROHF) total energy calculations with Hay- Wadt effective core potentials. The effects of electron correlation have been included using many-body perturbation theory through second order, with the exception of β(4 x 2) symmetry due to computational limitations. The semiconductor surface is modeled by finite sized hydrogen saturated clusters. The effects of surface relaxation and reconstruction have been investigated in detail. Results are given for the energetics of chemisorption, charge population analysis, HOMO-LUMO gaps, and consequent possibilities of metallization for atomic cesium adsorption. For the chemisorption of atomic hydrogen, the experimentally verified mechanism of surface dimer bond breaking is investigated in detail.

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

PubMed

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.

Laser-heated thruster

NASA Technical Reports Server (NTRS)

Kemp, N. H.; Lewis, P. F.

1980-01-01

The development of a computer program for the design of the thrust chamber for a CW laser heated thruster was examined. Hydrodgen was employed as the propellant gas and high temperature absorber. The laser absorption coefficient of the mixture/laser radiation combination is given in temperature and species densities. Radiative and absorptive properties are given to determine radiation from such gas mixtures. A computer code for calculating the axisymmetric channel flow of a gas mixture in chemical equilibrium, and laser energy absorption and convective and radiative heating is described. It is concluded that: (1) small amounts of cesium seed substantially increase the absorption coefficient of hydrogen; (2) cesium is a strong radiator and contributes greatly to radiation of cesium seeded hydrogen; (3) water vapor is a poor absorber; and (4) for 5.3mcm radiation, both H2O/CO and NO/CO seeded hydrogen mixtures are good absorbers.

Progress toward Brazilian cesium fountain second generation

NASA Astrophysics Data System (ADS)

Bueno, Caio; Rodriguez Salas, Andrés; Torres Müller, Stella; Bagnato, Vanderlei Salvador; Varela Magalhães, Daniel

2018-03-01

The operation of a Cesium fountain primary frequency standard is strongly influenced by the characteristics of two important subsystems. The first is a stable frequency reference and the second is the frequency-transfer system. A stable standard frequency reference is key factor for experiments that require high accuracy and precision. The frequency stability of this reference has a significant impact on the procedures for evaluating certain systematic biases in frequency standards. This paper presents the second generation of the Brazilian Cesium Fountain (Br-CsF) through the opto-mechanical assembly and vacuum chamber to trap atoms. We used a squared section glass profile to build the region where the atoms are trapped and colled by magneto-optical technique. The opto-mechanical system was reduced to increase stability and robustness. This newest Atomic Fountain is essential to contribute with time and frequency development in metrology systems.

Zero-multipole summation method for efficiently estimating electrostatic interactions in molecular system.

PubMed

Fukuda, Ikuo

2013-11-07

The zero-multipole summation method has been developed to efficiently evaluate the electrostatic Coulombic interactions of a point charge system. This summation prevents the electrically non-neutral multipole states that may artificially be generated by a simple cutoff truncation, which often causes large amounts of energetic noise and significant artifacts. The resulting energy function is represented by a constant term plus a simple pairwise summation, using a damped or undamped Coulombic pair potential function along with a polynomial of the distance between each particle pair. Thus, the implementation is straightforward and enables facile applications to high-performance computations. Any higher-order multipole moment can be taken into account in the neutrality principle, and it only affects the degree and coefficients of the polynomial and the constant term. The lowest and second moments correspond respectively to the Wolf zero-charge scheme and the zero-dipole summation scheme, which was previously proposed. Relationships with other non-Ewald methods are discussed, to validate the current method in their contexts. Good numerical efficiencies were easily obtained in the evaluation of Madelung constants of sodium chloride and cesium chloride crystals.

Electron-hole diffusion lengths >175 μm in solution-grown CH 3NH 3PbI 3 single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Qingfeng; Fang, Yanjun; Shao, Yuchuan

Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH 3NH 3PbI 3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH 3NH 3PbI 3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm –2) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smallermore » trap densities in the single crystals than in polycrystalline thin films. As a result, the long carrier diffusion lengths enabled the use of CH 3NH 3PbI 3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.« less