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Journal Articles

Design of microchannel suitable for packing with anion exchange resins; Uranium separation from seawater containing a large amount of cesium

Ouchi, Kazuki; Tsukahara, Takehiko*; Brandt, A.*; Muto, Yuki*; Nabatame, Nozomi*; Kitatsuji, Yoshihiro

Analytical Sciences, 37(12), p.1789 - 1794, 2021/12

 Times Cited Count:0 Percentile:0(Chemistry, Analytical)

We attempted to scale down a separation process of uranium (U) using the microchip column loaded with anion exchange resin to develop safety and waste-reducing separation technique. The ideal separation performance of U was obtained by the properly design of a microchannel. The concentration of U in seawater as a real-world sample could be quantified with the prepared microchip column. It indicates that the microchip column is sufficiently practical. Compared to separation of U with a general column, the column size was successfully scaled down to $$<$$ 1/5000.

Journal Articles

Numerical reproduction of dissolved U concentrations in a PO$$_{4}$$-treated column study of Hanford 300 area sediment using a simple ion exchange and immobile domain model

Saito, Tatsuo; Sato, Kazuhiko; Yamazawa, Hiromi*

Journal of Environmental Radioactivity, 237, p.106708_1 - 106708_9, 2021/10

 Times Cited Count:0 Percentile:0(Environmental Sciences)

We succeeded at numerical reproduction of dissolved U concentrations from column experiments with PO$$_{4}$$-treated Hanford 300 Area sediment. The time-series curves of dissolved U concentrations under various Darcy flow rate conditions were reproduced by the numerical model in the present study through optimization of the following parameters:(i) the mass of U in mobile domain (on surface soil connected to the stream) and the rest of the total U left as precipitation in immobile domain (isolated in deep soil);(ii) the mixing ratio between immobile and mobile domains, to fit the final recovering curve of concentration; and (iii) the cation exchange capacity (CEC$$_{Zp}$$) and equilibrium constant (k$$_{Zp}$$) of the exchange reaction of UO$$_{2}$$$$^{2+}$$ and H$$^{+}$$ on simulated soil surface ($$Zp$$), to fit the transient equilibrium concentration, forming the bed of the bathtub curve.

Journal Articles

Dependence of charge-exchange efficiency on cooling water temperature of a beam transport line

Yamamoto, Kazami; Hatakeyama, Shuichiro; Saha, P. K.; Moriya, Katsuhiro; Okabe, Kota; Yoshimoto, Masahiro; Nakanoya, Takamitsu; Fujirai, Kosuke; Yamazaki, Yoshio; Suganuma, Kazuaki

EPJ Techniques and Instrumentation (Internet), 8(1), p.9_1 - 9_9, 2021/07

The 3 GeV Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex supplies a high-intensity proton beam for neutron experiments. Various parameters are monitored to achieve a stable operation, and it was found that the oscillations of the charge-exchange efficiency and cooling water temperature were synchronized. We evaluated the orbit fluctuations at the injection point using a beam current of the injection dump, which is proportional to the number of particles that miss the foil and fail in the charge exchange, and profile of the injection beam. The total width of the fluctuations was approximately 0.072 mm. This value is negligible from the user operation viewpoint as our existing beam position monitors cannot detect such a small signal deviation. This displacement corresponds to a 1.63$$times$$10$$^{-5}$$ variation in the dipole magnetic field. Conversely, the magnetic field variation in the L3BT dipole magnet, which was estimated by the temperature change directly, is 4.08$$times$$10$$^{-5}$$. This result suggested that the change in the cooling water temperature is one of the major causes of the efficiency fluctuation.

Journal Articles

Effect of interlayer cations on montmorillonite swelling; Comparison between molecular dynamic simulations and experiments

Yotsuji, Kenji*; Tachi, Yukio; Sakuma, Hiroshi*; Kawamura, Katsuyuki*

Applied Clay Science, 204, p.106034_1 - 106034_13, 2021/04

 Times Cited Count:17 Percentile:99.38(Chemistry, Physical)

Journal Articles

Study of neutron-nuclear spin correlation term with a polarized Xe target

Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kakurai, Kazuhisa*; Shimizu, Hirohiko*; Hirota, Katsuya*; et al.

JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03

In neutron fundamental physics, study of correlation term $${bf s}cdot{bf I}$$ of a neutron spin $${bf s}$$ and a target nuclear spin $${bf I}$$ is important because $${bf s}cdot{bf I}$$ term interferes to parity non-conserving (PNC) and time reversal non-conserving terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to $$ sim 10^{-1}$$ by using a spin exchange optical pumping (SEOP) method. We would plan to develop a polarized Xe gas target with a compact in-situ SEOP system, and to study $${bf s}cdot{bf I}$$ term by utilizing epithermal neutron beams supplied from a high intense pulsed spallation neutron source. As the first step, we attempted to measure neutron polarizing ability caused by $${bf s}cdot{bf I}$$ term at a 9.6 eV s-wave resonance peak of $$^{129}$$Xe at BL10 in MLF, by detecting change $$Delta R$$ of ratio between neutron transmissions with the polarized and unpolarized Xe target. After demonstrating that our apparatus could detect small change ($$Delta R_{rm DB} , {approx},10^{-2}$$) of neutron transmissions caused by Doppler broadening effect, a signified value of $$Delta R$$ has been obtained as preliminary results. For analyzing the obtained $$Delta R$$ in detail, we are improving our nuclear magnetic resonance and electron paramagnetic resonance systems for evaluating Xe polarization independently of neutron beams.

JAEA Reports

Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2019

Nishio, Kazuhisa*; Shimizu, Mayuko; Iyatomi, Yosuke; Hama, Katsuhiro

JAEA-Review 2020-013, 59 Pages, 2020/08

JAEA-Review-2020-013.pdf:19.64MB

The Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA) has been conducting geoscientific study in order to establish a scientific and technological basis for the geological disposal of HLW. Technical information of the result on the geoscientific study conducted at TGC is provided at the annual Information and Opinion Exchange Conference on Geoscientific Study of TGC for exchanging opinions among researchers and engineers from universities, research organizations and private companies. This document compiles the research presentations and posters of the conference in Mizunami on November 20, 2019.

Journal Articles

Preliminary analysis of sodium experimental apparatus PLANDTL-2 for development of evaluation method for thermal-hydraulics in reactor vessel of sodium fast reactor under decay heat removal system operation condition

Ono, Ayako; Tanaka, Masaaki; Miyake, Yasuhiro*; Hamase, Erina; Ezure, Toshiki

Mechanical Engineering Journal (Internet), 7(3), p.19-00546_1 - 19-00546_11, 2020/06

Fully natural circulation decay heat removal systems (DHRSs) are to be adopted for sodium fast reactors, which is a passive safety feature without any electrical pumps. It is required to grasp the thermal-hydraulic phenomena in the reactor vessel and evaluate the coolability of the core under the natural circulation not only for the normal operating condition but also for severe accident conditions. In this paper, the numerical results of the preliminary analysis for the sodium experimental condition with the PLANDTL-2 are discussed to establish an appropriate numerical models for the reactor core including the gap region among the subassemblies and the DHX. From these preliminary analyses, the characteristics of the thermal-hydraulics behavior in the PLANDTL-2 to be focused are extracted.

Journal Articles

Preliminary analysis of sodium experimental apparatus PLANDTL-2 for development of evaluation method for thermal hydraulics in reactor vessel of sodium fast reactor under decay heat removal system operation condition

Ono, Ayako; Tanaka, Masaaki; Miyake, Yasuhiro*; Hamase, Erina; Ezure, Toshiki

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 7 Pages, 2019/05

Decay heat removal system (DHRS) by using the natural circulation without depending on the pump as the mechanical equipment is recognized as one of the most effective methodologies for the sodium-cooled fast reactor from the viewpoint of the safety enhancement. In this paper, the numerical simulation results of the preliminary analysis for the sodium experiment with the apparatus of PLANDTL-2, in which the core and the upper plenum with a dipped-type direct heat exchanger (DHX) were modeled, were discussed, in order to establish appropriate numerical models for the reactor core including the gap region among the subassemblies and the DHX.

JAEA Reports

Memoirs; The Energy Technology Data Exchange (ETDE) for Japan

Kunii, Katsuhiko; Itabashi, Keizo; Yonezawa, Minoru

JAEA-Review 2019-002, 237 Pages, 2019/03

JAEA-Review-2019-002.pdf:8.2MB

From 1987 to 2014, the Energy Technology Data Exchange (ETDE) Program under the auspices of the International Energy Agency (IEA) had been carried out successfully with fruitful outcomes. ETDE had been able to be an excellent database for use in the general field of application of energy, including nuclear energy. ETDE could have deserved it, by extensively collecting the literature and providing the metadata worldwide, as well as by delivering and disseminating the bibliographic data, first to member countries, next additionally to the developing countries free of charge and finally all the world through the Internet free of charge as well. During all the days of ETDE Program Then ETDE had been very close and strong ties and cooperation with the International Nuclear Information System (INIS) Program under the auspices of the International Atomic Energy Agency (IAEA), e.g., by sharing and complementing many elements and parts of each database mutually. A portal site, the ETDE World Energy Base (ETDEWEB), for the database of ETDE, had been available for use to deliver and disseminate the valuable information of bibliography of ETDE, containing directions to the full text data, dedicated to satisfying the interest of end users worldwide. As of today, even if the addition of bibliographic data to ETDE has ceased since 2014, ETDEWEB itself has been available as before, maintained in great help of the Office of Scientific and Technical Information (OSTI) of the Department of Energy (DOE), US, while OSTI had been praised as the Operating Agent (OA) of ETDE Program from the commencement to the ceasing. This is a report containing several historical documents in regard with the ETDE activities worldwide kept and remained in Japan as records (minutes etc) at the side of JAERI.

Journal Articles

Characterization of mineralogical controls on ammonium concentrations in deep groundwaters of the Horonobe area, Hokkaido

Sasamoto, Hiroshi; Sato, Hisao*; Arthur, R. C.*

Journal of Geochemical Exploration, 188, p.318 - 325, 2018/05

 Times Cited Count:0 Percentile:0.01(Geochemistry & Geophysics)

Ammonium is potentially an important constituent of deep groundwater under reducing condition. The retention of cesium by sorption in geological formations may have an important role ensuring the long-term safety of high-level radioactive waste. Cesium sorption will be affected by competing effects due to dissolve cation likely ammonium in groundwater, however. In the present study, a possible reaction to control of ammonium in deep groundwater was evaluated based on the data selected in the Horonobe as a test case in Japan. Results of investigation of mineralogy, thermodynamic evaluation of groundwaters and the Electron Probe Micro Analysis (EPMA) to identify nitrogen distribution on minerals suggest that the clay minerals bearing potassium, particularly smectite, illite and interstratified illite/smectite, appear to control the ammonium concentration in groundwaters by ion exchange reactions. Additionally, the selected groundwaters in the Horonobe seem to resemble to the gas and oil fields groundwater in the screened dataset in Japan in terms of ammonium distribution.

Journal Articles

Examination of analytical method of rare earth elements in used nuclear fuel

Ozawa, Mayumi; Fukaya, Hiroyuki; Sato, Makoto; Kamohara, Keiko*; Suyama, Kenya; Tonoike, Kotaro; Oki, Keiichi; Umeda, Miki

Proceedings of 53rd Annual Meeting of Hot Laboratories and Remote Handling Working Group (HOTLAB 2016) (Internet), 9 Pages, 2016/11

Journal Articles

Sorption of Eu$$^{3+}$$ on Na-montmorillonite studied by time-resolved laser fluorescence spectroscopy and surface complexation modeling

Sasaki, Takayuki*; Ueda, Kenyo*; Saito, Takumi; Aoyagi, Noboru; Kobayashi, Taishi*; Takagi, Ikuji*; Kimura, Takaumi; Tachi, Yukio

Journal of Nuclear Science and Technology, 53(4), p.592 - 601, 2016/04

 Times Cited Count:12 Percentile:80.58(Nuclear Science & Technology)

The influences of pH and the concentrations of Eu$$^{3+}$$ and NaNO$$_{3}$$ on the sorption of Eu$$^{3+}$$ to Na-montmorillonite were investigated through batch sorption measurements and time-resolved laser fluorescence spectroscopy (TRLFS). The pH had a little effect on the distribution coefficients (Kd) in 0.01 M NaNO$$_{3}$$, whereas the Kd strongly depended on pH at 1 M NaNO$$_{3}$$. A cation exchange model combined with a one-site non-electrostatic surface complexation model was successfully applied to the measured Kd. The TRLFS spectra of Eu$$^{3+}$$ sorbed were processed by parallel factor analysis (PARAFAC), which corresponded to one outer-sphere (factor A) and two inner-sphere (factor B and C) complexes. It turned out that factors A and B correspond to Eu$$^{3+}$$ sorbed by ion exchange sites and inner-sphere complexation with hydroxyl groups of the edge faces, respectively. Factor C became dominant at relatively high pH and ionic strength and likely correspond to the precipitation of Eu(OH)$$_{3}$$ on the surface.

Journal Articles

Imidazolium-based anion exchange membranes for alkaline anion fuel cells; Elucidation of the morphology and the interplay between the morphology and properties

Zhao, Y.; Yoshimura, Kimio; Shishitani, Hideyuki*; Yamaguchi, Susumu*; Tanaka, Hirohisa*; Koizumi, Satoshi*; Szekely, N.*; Radulescu, A.*; Richter, D.*; Maekawa, Yasunari

Soft Matter, 12(5), p.1567 - 1578, 2016/02

 Times Cited Count:23 Percentile:81.06(Chemistry, Physical)

Journal Articles

Synthesis of sodium dodecyl sulfate-supported nanocomposite cation exchanger; Removal and recovery of Cu$$^{2+}$$ from synthetic, pharmaceutical and alloy samples

Naushad, M.*; Alothman, Z. A.*; Alam, M. M.*; Awual, M. R.; Eldesoky, G. E.*; Islam, M.*

Journal of the Iranian Chemical Society, 12(9), p.1677 - 1686, 2015/09

 Times Cited Count:42 Percentile:79.76(Chemistry, Multidisciplinary)

Journal Articles

Hydrogen permeation through heat transfer pipes made of Hastelloy XR during the initial 950$$^{circ}$$C operation of the HTTR

Sakaba, Nariaki; Ohashi, Hirofumi; Takeda, Tetsuaki

Journal of Nuclear Materials, 353(1-2), p.42 - 51, 2006/07

 Times Cited Count:6 Percentile:42.84(Materials Science, Multidisciplinary)

The permeation of hydrogen isotopes through the Hastelloy XR high-temperature alloy adopted for the heat transfer pipes of the intermediate heat exchanger in the HTTR, is one of the concerns in the hydrogen production system, which will be connected to the HTTR in the near future. The hydrogen permeation between the primary and secondary coolant through the Hastelloy XR was evaluated using the actual hydrogen concentration observed during the initial 950$$^{circ}$$C operation of the HTTR. The hydrogen permeability of the Hastelloy XR was estimated conservatively high as follows. The activation energy E$$_{0}$$ and pre-exponential factor F$$_{0}$$ of the permeability of hydrogen were E$$_{0}$$ = 65.8 kJ/mol and F$$_{0}$$ = 7.8$$times$$10$$^{-9}$$m$$^{3}$$(STP)/(m$$ast$$s$$ast$$Pa$$^{0.5}$$), respectively, in the temperature range from 707K to 900K.

Journal Articles

Synthesis and characterization of nickel-copper hydroxide acetate, NiCu(OH)$$_{3.1}$$(OCOCH$$_{3}$$)$$_{0.9}$$ $$cdot$$ 0.9H$$_{2}$$O

Kozai, Naofumi; Mitamura, Hisayoshi; Fukuyama, Hiroyasu; Esaka, Fumitaka; Komarneni, S.*

Microporous and Mesoporous Materials, 89(1-3), p.123 - 131, 2006/03

 Times Cited Count:10 Percentile:38.24(Chemistry, Applied)

Layered transition metal hydroxide salt (LTMHS) is a group of anion-exchangeable layered compounds. Although LTMHSs have recentely attracted attention of researches on anion exchange and intercalation, very limited numbers of reports have been published on their synthesis, characteristics, and applications. This paper describes basic characteristics of a new LTMHS, nickel-copper hydroxide acetate. Hydrothermal Heating of an aqueous solution containing nickel acetate, copper acetate, and hydrogen peroxide to 150$$^{o}$$C for 4h yielded a layered compound with an analytical composition of NiCu(OH)$$_{3.1}$$(OCOCH$$_{3}$$)$$_{0.9}$$ 0.9H$$_{2}$$O. This compound does not take up Cl$$^{-}$$ and NO$$_{3}$$$$^{-}$$ in aqueous solution but takes up multivalent anions and shows high selectivity in uptake of toxic SeO$$_{3}$$$$^{2-}$$ and AsO$$_{4}$$$$^{3-}$$. This compound may find applicarion in the removal of those toxic anions form natural water and wastewater rich in Cl$$^{-}$$ and NO$$_{3}$$$$^{-}$$.

Journal Articles

Recent results on hydrogen and hydration in biology studied by neutron macromolecular crystallography

Niimura, Nobuo; Arai, Shigeki; Kurihara, Kazuo; Chatake, Toshiyuki*; Tanaka, Ichiro*; Bau, R.*

Cellular and Molecular Life Sciences, 63(3), p.285 - 300, 2006/02

 Times Cited Count:41 Percentile:39.36(Biochemistry & Molecular Biology)

Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins and DNA oligomers. Three different types of high resolution neutron diffractometers for biological macromolecules have been constructed in Japan, France and the U.S.A., and they have all been actively used in recent years to determine the crystal structures of numerous proteins. Examples include the detailed geometries of hydrogen bonds, information on H/D exchange in proteins, the unambiguous location of protons, the role of key hydrogen atoms in enzymatic activity and thermostability, and the dynamical behavior of hydration structures, all of which have been extracted from these structural results and reviewed in this article. Other important techniques, such as the optimization of growth of large single crystals using phase diagrams, the preparation of fully deuterated proteins, the introduction of cryogenic techniques to neutron protein crystallography, and the establishment of a "hydrogen and hydration in proteins" database, will also be described in this paper.

Journal Articles

Production and compilation of charge changing cross sections of ion-atom and ion-molecule collisions

Imai, Makoto*; Shirai, Toshizo*; Saito, Manabu*; Haruyama, Yoichi*; Ito, Akio*; Imanishi, Nobutsugu*; Fukuzawa, Fumio*; Kubo, Hirotaka

Journal of Plasma and Fusion Research SERIES, Vol.7, p.323 - 326, 2006/00

no abstracts in English

Journal Articles

Incorporation of CO$$_{2}$$ exchange processes into a multilayer atmosphere-soil-vegetation model

Nagai, Haruyasu

Journal of Applied Meteorology, 44(10), p.1574 - 1592, 2005/10

This paper describes the incorporation of CO$$_{2}$$ exchange processes into an atmosphere-soil-vegetation model SOLVEG and examination of its sensitivity and impact of its stomatal resistance calculation on the latent heat flux over a winter wheat field. The model framework for the heat and water exchanges between the atmosphere and ground surface was validated in the previous papers (Nagai 2002, 2003). In this study, CO$$_{2}$$ exchange processes are incorporated in the model and the performance is examined. In the test calculation, the model simulated the CO$$_{2}$$ flux at 2 m above the ground well as a whole. A sensitivity test to clarify uncertainties for the model settings and parameters showed that the CO$$_{2}$$ production in the soil is the most important factor for the CO$$_{2}$$ calculation. Also, the impact of the CO$$_{2}$$ processes on the latent heat flux is discussed. The results indicate that the new model is effective and preferable to study surface exchanges of heat and water as well as CO$$_{2}$$.

Journal Articles

Structural integrity assessments of helium components in the primary cooling system during the safety demonstration test using the HTTR

Sakaba, Nariaki; Tachibana, Yukio; Nakagawa, Shigeaki; Hamamoto, Shimpei

Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18), p.4499 - 4511, 2005/08

Safety demonstration tests using the HTTR are now underway in order to verify the inherent safety features and to improve the safety design and evaluation technologies for HTGRs, as well as to contribute to research and development for the VHTR, which is one of the Generation IV reactor candidates. The coolant flow reduction test by running down gas circulators, which is one of the safety demonstration tests, is a simulation test of anticipated transients without scram. During the coolant flow reduction test, temperature of the high-temperature helium components and chemistry in the primary circuit are changed rapidly. This paper describes the structural integrity assessments of helium components, e.g. helium pipes, heat exchangers, during the coolant flow reduction test. From the result of this evaluation, it was found that the helium components were kept their structural integrity during temperature and chemistry transient condition in the coolant flow reduction test from the reactor power at 30%. It was also confirmed by this assessment that the coolant flow reduction test will be able to perform with its enough safety margins from the reactor power at 100%.

163 (Records 1-20 displayed on this page)