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Journal Articles

Research and development on membrane IS process for hydrogen production using solar heat

Odtsetseg, M.; Iwatsuki, Jin; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Ioka, Ikuo; Kubo, Shinji; Nomura, Mikihiro*; Yamaki, Tetsuya*; Sawada, Shinichi*; et al.

International Journal of Hydrogen Energy, 44(35), p.19141 - 19152, 2019/07

Journal Articles

Development of container using plasma sprayed and laser treated material for sulfuric acid decomposition of thermochemical water-splitting iodine-sulfur process

Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Inagaki, Yoshiyuki; Sakaba, Nariaki

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 5 Pages, 2019/05

A thermochemical water-splitting iodine-sulfur processes (IS process) is one of candidates for the large-scale production of hydrogen using heat from solar power. Severe corrosive environment which is thermal decomposition of sulfuric acid exists in the IS process. A hybrid material with the corrosion-resistance and the ductility was made by a plasma spraying and laser treatment. The specimen had excellent corrosion resistance in the condition of 95 mass% boiling sulfuric acid. This was attributed to the formation of SiO$$_{2}$$ on the surface. To confirm the production characteristics of a container using the hybrid material, the container which has a welded part, a chamfer, a curved surface was experimentally made. There was no detachment in the plasma spraying and laser treated layer of the container after the laser treatment.

Journal Articles

A Conceptual design study of pool-type sodium-cooled fast reactor with enhanced anti-seismic capability

Kubo, Shigenobu; Chikazawa, Yoshitaka; Ohshima, Hiroyuki; Uchida, Masato*; Miyagawa, Takayuki*; Eto, Masao*; Suzuno, Tetsuji*; Matoba, Ichiyo*; Endo, Junji*; Watanabe, Osamu*; et al.

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 8 Pages, 2019/05

The authors are developing the design concept of pool-type sodium-cooled fast reactor (SFR) that addresses Japan's specific siting conditions such as earthquakes and meets safety design criteria (SDC) and safety design guidelines (SDGs) for Generation IV SFRs. The development of this concept will broaden not only options for reactor types in Japan but also the range and depth of international cooperation. A design concept of 1,500 MWt (650 MWe) class pool-type SFR was thought up by applying design technology obtained from the design of advanced loop-type SFR, named JSFR, equipped with safety measures that reflect results from the feasibility study on commercialized fast reactor cycle systems and fast reactor cycle technology development, improved maintainability and repairability, and lessons learned from the Fukushima Daiichi Nuclear Power Plants accident.

Journal Articles

Module design of silica membrane reactor for hydrogen production via thermochemical IS process

Odtsetseg, M.; Tanaka, Nobuyuki; Nomura, Mikihiro*; Kubo, Shinji

International Journal of Hydrogen Energy, 44(21), p.10207 - 10217, 2019/04

Journal Articles

Structure of nitride layer formed on titanium alloy surface by N$$_{2}$$-gas exposure at high temperatures

Takeda, Yusuke; Iida, Kiyoshi*; Sato, Shinji*; Matsuo, Tadatoshi*; Nagashima, Yasuyuki*; Okubo, Nariaki; Kondo, Keietsu; Hirade, Tetsuya

JPS Conference Proceedings (Internet), 25, p.011023_1 - 011023_3, 2019/03

In this study, we prepared samples under two different conditions, (1) 810$$^{circ}$$C, for 600 min, and (2) 850$$^{circ}$$C, for 720 min. A depth-profile analysis of the surfaces of the samples is conducted through Doppler broadening (DB) measurements of positron annihilation $$gamma$$ rays using a slow positron beam. It was indicated that many of positrons annihilated in defects near the surface. According to the TEM image, there are nano-crystal grains near the surface and then positrons can diffuse in the grains and annihilate in defects at the grain boundaries. Furthermore, DB measurements indicated that there is a depth dependence on the chemical composition where positrons annihilate. EDS spectroscopy measurements also indicated that there is a depth dependence of impurities such as Vanadium. These results indicated change of the chemical composition at the grain boundaries.

Journal Articles

Nowcast and forecast of galactic cosmic ray (GCR) and solar energetic particle (SEP) fluxes in magnetosphere and ionosphere; Extension of WASAVIES to earth orbit

Sato, Tatsuhiko; Kataoka, Ryuho*; Shiota, Daiko*; Kubo, Yuki*; Ishii, Mamoru*; Yasuda, Hiroshi*; Miyake, Shoko*; Miyoshi, Yoshizumi*; Ueno, Haruka*; Nagamatsu, Aiko*

Journal of Space Weather and Space Climate (Internet), 9, p.A9_1 - A9_11, 2019/03

Real-time estimation of astronaut doses during solar particle events (SPE) is one of the most challenging tasks in cosmic-ray dosimetry. We therefore develop a new computational method that can nowcast the solar energetic particle (SEP) as well as galactic cosmic-ray (GCR) fluxes on any Earth orbit during a large SPE associating with ground level enhancement. It is an extended version of WArning System for AVIation Exposure to Solar Energetic Particle, WASAVIES. The extended version, called WASAVIES-EO, can calculate the GCR and SEP fluxes outside a satellite based on its two-line element data. Moreover, organ dose and dose-equivalent rates of astronauts in the International Space Station (ISS) can be estimated using the system, considering its shielding effect. The accuracy of WASAVIES-EO was validated based on the dose rates measured in ISS, as well as based on high-energy proton fluxes observed by POES satellites.

Journal Articles

New insights into the Cs adsorption on montmorillonite clay from $$^{133}$$Cs solid-state NMR and density functional theory calculations

Okubo, Takahiro*; Okamoto, Takuya*; Kawamura, Katsuyuki*; Gu$'e$gan, R.*; Deguchi, Kenzo*; Oki, Shinobu*; Shimizu, Tadashi*; Tachi, Yukio; Iwadate, Yasuhiko*

Journal of Physical Chemistry A, 122(48), p.9326 - 9337, 2018/12

 Percentile:100(Chemistry, Physical)

The structures of Cs adsorption on montmorillonite were investigated by the nuclear magnetic resonance (NMR) spectroscopy. The NMR spectra of Cs adsorbed on montmorillonite samples were measured under different Cs contents and relative humidity levels. NMR parameters were evaluated by the first principle calculations in order to identify the relationship between adsorbed Cs structures and NMR parameters. The comparisons between experimental and theoretical NMR spectra revealed that Cs is preferentially adsorbed at sites near Al for low Cs substituted montmorillonites, and that non-hydrated Cs present in partially Cs substituted samples, even after being hydrated under high relative humidity.

Journal Articles

Current R&D status of thermochemical water splitting hydrogen production iodine-sulfur process in Japan Atomic Energy Agency, 1; Hydrogen production test and component development

Takegami, Hiroaki; Noguchi, Hiroki; Tanaka, Nobuyuki; Iwatsuki, Jin; Kamiji, Yu; Kasahara, Seiji; Imai, Yoshiyuki; Terada, Atsuhiko; Kubo, Shinji

Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10

Japan Atomic Energy Agency (JAEA) has been conducting R&D on the thermochemical iodine-sulfur (IS) process for nuclear-powered hydrogen production. The IS process is one of the promising candidates of heat application of the high-temperature gas-cooled reactors. JAEA fabricated main chemical reactors made of industrial structural materials and confirmed their integrity in practical corrosive environments in the IS process. Based on the results of these confirmation tests, JAEA have constructed a 100 NL/h-H$$_{2}$$-scale test facility made of industrial structural materials. This report will present an outline and results of hydrogen production tests and reliability improvements of operation stability and components, such as development of a strength estimation method for heat-resistant and corrosion-resistant ceramics components made of silicon carbide.

Journal Articles

Current R&D status of thermochemical water splitting hydrogen production iodine-sulfur process in Japan Atomic Energy Agency, 2; Reliability improvements of corrosion-resistant equipment

Kamiji, Yu; Noguchi, Hiroki; Takegami, Hiroaki; Tanaka, Nobuyuki; Iwatsuki, Jin; Kasahara, Seiji; Kubo, Shinji

Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10

Japan Atomic Energy Agency (JAEA) has been conducting R&D on the thermochemical iodine-sulfur (IS) process for nuclear-powered hydrogen production. The IS process is one of the promising candidates of heat application of the HTGR. JAEA achieved continuous hydrogen production for one week with a hydrogen production rate of 30 NL/h by using a test apparatus made of glass and fluororesin material. Subsequently, JAEA fabricated main chemical reactors made of industrial materials and confirmed their integrity in corrosive environments in the IS process. Based on the results, JAEA has constructed a 100 NL/h-H$$_{2}$$-scale test facility made of industrial materials; one of the important materials is the glass-lined steel for corrosion resistant components such as vessels, pipes and protective sheaths of sensors. This report will present technical matters to improve reliability of the glass-lined protective sheaths of thermocouple. In addition, results of quality confirmation will be presented, which are stress analyses for the glass layer by FEM, tests for heat cycle, bending load and corrosion.

Journal Articles

Development of ion-exchange membranes for the membrane Bunsen reaction in thermochemical hydrogen production by iodine-sulfur process

Nomura, Mikihiro*; Kodaira, Takahide*; Ikeda, Ayumi*; Naka, Yasuhito*; Nishijima, Haruyuki*; Imabayashi, Shinichiro*; Sawada, Shinichi*; Yamaki, Tetsuya*; Tanaka, Nobuyuki; Kubo, Shinji

Journal of Chemical Engineering of Japan, 51(9), p.726 - 731, 2018/09

 Percentile:100(Engineering, Chemical)

Thermochemical hydrogen production by the iodine-sulfur process decomposes water into hydrogen and oxygen by combining the chemical reactions of iodine and sulfur. Two types of acids are produced through the Bunsen reaction. To improve the performance of this reaction, ion-exchange membranes for the membrane Bunsen reaction should be developed. In the present study, a cation-exchange membrane was prepared by using a radiation-graft polymerization method. It was found that a divinylbenzene crosslinking procedure was very effective in reducing water permeation through the membrane, and the membrane Bunsen reaction was successfully carried out by using the developed crosslinked membrane. Therefore, the developed crosslinked membrane is a potential candidate for cation-exchange membranes for the membrane Bunsen reaction.

JAEA Reports

Excellent feature of Japanese HTGR technologies

Nishihara, Tetsuo; Yan, X.; Tachibana, Yukio; Shibata, Taiju; Ohashi, Hirofumi; Kubo, Shinji; Inaba, Yoshitomo; Nakagawa, Shigeaki; Goto, Minoru; Ueta, Shohei; et al.

JAEA-Technology 2018-004, 182 Pages, 2018/07

JAEA-Technology-2018-004.pdf:18.14MB

Research and development on High Temperature Gas-cooled Reactor (HTGR) in Japan started since late 1960s. Japan Atomic Energy Agency (JAEA) in cooperation with Japanese industries has researched and developed system design, fuel, graphite, metallic material, reactor engineering, high temperature components, high temperature irradiation and post irradiation test of fuel and graphite, high temperature heat application and so on. Construction of the first Japanese HTGR, High Temperature engineering Test Reactor (HTTR), started in 1990. HTTR achieved first criticality in 1998. After that, various test operations have been carried out to establish the Japanese HTGR technologies and to verify the inherent safety features of HTGR. This report presents several system design of HTGR, the world-highest-level Japanese HTGR technologies, JAEA's knowledge obtained from construction, operation and management of HTTR and heat application technologies for HTGR.

Journal Articles

Radiation dose nowcast for the ground level enhancement on 10-11 September 2017

Kataoka, Ryuho*; Sato, Tatsuhiko; Miyake, Shoko*; Shiota, Daiko*; Kubo, Yuki*

Space Weather, 16(7), p.917 - 923, 2018/07

 Times Cited Count:8 Percentile:2.3(Astronomy & Astrophysics)

A ground level enhancement (GLE) event occurred on 10-11 September 2017, associated with X8.2 solar flare exploded at western limb. The magnitude of the GLE was not so large even at the peak, but the duration of the event was longer than average. We briefly report the results of our manually conducted nowcast using WASAVIES (Warning System of AViation Exposure to Solar energetic particles). The maximum radiation dose rate at 12 km flight altitude was estimated to be approximately 2 $$mu$$Sv/h, which is only one-third of the corresponding background dose rate due to the galactic cosmic-ray exposure. This result verified the safety of aircrews and passengers in aviation during this event.

Journal Articles

Real time and automatic analysis program for WASAVIES; Warning system for aviation exposure to solar energetic particles

Sato, Tatsuhiko; Kataoka, Ryuho*; Shiota, Daiko*; Kubo, Yuki*; Ishii, Mamoru*; Yasuda, Hiroshi*; Miyake, Shoko*; Park, I.*; Miyoshi, Yoshizumi*

Space Weather, 16(7), p.924 - 936, 2018/07

 Times Cited Count:4 Percentile:11.05(Astronomy & Astrophysics)

A physics-based warning system of aviation exposure to solar energetic particles, WASAVIES, is improved to be capable of real-time and automatic analysis. In the improved system, the count rates of several neutron monitors (NM) at the ground level, as well as the proton fluxes measured by the GOES satellite are continuously downloaded at intervals of 5 min and used for determining the model parameters. The performance of WASAVIES is examined by analyzing the three major GLE events of the 21st century. A web-interface of WASAVIES is also developed and will be released in the near future through the public server of NICT.

Journal Articles

Termination of electron acceleration in thundercloud by intracloud/intercloud discharge

Wada, Yuki*; Bowers, G. S.*; Enoto, Teruaki*; Kamogawa, Masashi*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Smith, D.*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; et al.

Geophysical Research Letters, 45(11), p.5700 - 5707, 2018/06

 Times Cited Count:1 Percentile:53.8(Geosciences, Multidisciplinary)

Journal Articles

Status report of the chopper spectrometer 4SEASONS

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Murai, Naoki; Kira, Hiroshi*; Nakatani, Takeshi; et al.

Journal of Physics; Conference Series, 1021(1), p.012030_1 - 012030_6, 2018/06

Journal Articles

Preheat effect on titanium plate fabricated by sputter-free selective laser melting in vacuum

Sato, Yuji*; Tsukamoto, Masahiro*; Shobu, Takahisa; Yamashita, Yoshihiro*; Yamagata, Shuto*; Nishi, Takaya*; Higashino, Ritsuko*; Okubo, Tomomasa*; Nakano, Hitoshi*; Abe, Nobuyuki*

Applied Physics A, 124(4), p.288_1 - 288_6, 2018/04

 Times Cited Count:1 Percentile:59.26(Materials Science, Multidisciplinary)

The dynamics of titanium (Ti) melted by laser irradiation was investigated in a synchrotron radiation experiment. As an indicator of wettability, the contact angle between a selective laser melting (SLM) baseplate and the molten Ti was measured by synchrotron X-rays at 30 keV during laser irradiation. As the baseplate temperature increased, the contact angle decreased, down to 28 degrees at a baseplate temperature of 500$$^{circ}$$C. Based on this result, the influence of wettability of a Ti plate fabricated by SLM in a vacuum was investigated. It was revealed that the improvement of wettability by preheating suppressed sputtering generation, and a surface having a small surface roughness was fabricated by SLM in a vacuum.

Journal Articles

Seismic evaluation for a large-sized reactor vessel targeting SFRs in Japan

Uchida, Masato*; Miyagawa, Takayuki*; Dozaki, Koji*; Chikazawa, Yoshitaka; Kubo, Shigenobu; Hayafune, Hiroki; Suzuno, Tetsuji*; Fukasawa, Tsuyoshi*; Kamishima, Yoshio*; Fujita, Satoshi*

Proceedings of 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) (CD-ROM), p.380 - 386, 2018/04

It is well-known that pool-type SFRs are the main streams recently in a field of Generation IV reactors. The pool-type encloses primary pumps and IHXs located around the core barrel in a main vessel. Consequently, the main vessel diameter trends to be larger than that of loop-types. From the viewpoint of commercialization in the future, a target of the vessel diameter and its weight including Sodium coolant will increase further. In this paper, the prospects are described in terms of seismic design and structural integrity for the thermal loadings to prevent buckling of the reactor vessel based on parameter studies with diameters of the vessel. In addition, the seismic isolation device which will be effective as a countermeasure is proposed in order to secure a margin against buckling of a large reactor vessel.

Journal Articles

R&D status in thermochemical water-splitting hydrogen production iodine-sulfur process at JAEA

Noguchi, Hiroki; Takegami, Hiroaki; Kasahara, Seiji; Tanaka, Nobuyuki; Kamiji, Yu; Iwatsuki, Jin; Aita, Hideki; Kubo, Shinji

Energy Procedia, 131, p.113 - 118, 2017/12

 Times Cited Count:3 Percentile:1.43

The IS process is the most deeply investigated thermochemical water-splitting hydrogen production cycle. It is in a process engineering stage in JAEA to use industrial materials for components. Important engineering tasks are verification of integrity of the total process and stability of hydrogen production in harsh environment. A test facility using corrosion-resistant materials was constructed. The hydrogen production ability was 100 L/h. Operation tests of each section were conducted to confirm basic functions of reactors and separators, etc. Then, a trial operation for integration of the sections was successfully conducted to produce hydrogen of about 10 L/h for 8 hours.

Journal Articles

Hydrogen production tests by hydrogen iodide decomposition membrane reactor equipped with silica-based ceramics membrane

Odtsetseg, M.; Tanaka, Nobuyuki; Nomura, Mikihiro*; Kubo, Shinji

International Journal of Hydrogen Energy, 42(49), p.29091 - 29100, 2017/12

 Times Cited Count:2 Percentile:76.91(Chemistry, Physical)

The catalytic decomposition of hydrogen iodide in a membrane reactor using silica membranes derived from hexyltrimethoxysilane (HTMOS) was investigated for the production of hydrogen in the thermochemical water splitting iodine-sulfur process. The silica membranes were prepared by counter-diffusion chemical vapor deposition using porous alumina support tubes in both the absence and presence of a $$gamma$$-alumina layer. The silica membranes formed on $$gamma$$-alumina-coated $$alpha$$-alumina tubes displayed a higher H$$_{2}$$ permeance than that formed directly on an $$alpha$$-alumina tube. A silica membrane based on a 1.5 $$mu$$m-thick $$gamma$$-alumina layer fabricated under deposition conditions of 450$$^{circ}$$C, 1200 s, and a N$$_{2}$$ carrier gas velocity of 0.044 m s$$^{-1}$$ exhibited a high H$$_{2}$$ permeance of 9.4 $$times$$ 10$$^{-7}$$ mol Pa$$^{-1}$$ m$$^{-2}$$ s$$^{-1}$$ while maintaining an H$$_{2}$$/N$$_{2}$$ selectivity of over 80.0. The performance of a membrane reactor based on an HTMOS-derived silica membrane was evaluated at 400$$^{circ}$$C by measuring the HI conversion and H$$_{2}$$ flow rates. The conversion was approximately 0.48 when the HI flow rate was 9.7 mL min$$^{-1}$$.

Journal Articles

New precise measurement of muonium hyperfine structure interval at J-PARC

Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11

 Times Cited Count:1 Percentile:17.79

766 (Records 1-20 displayed on this page)