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Journal Articles

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

Myagmarjav, O.; 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

 Times Cited Count:12 Percentile:67.04(Chemistry, Physical)

JAEA Reports

Characteristics of pore formers in low density MOX pellet fabrication

Mizuno, Mineo; Haga, Tetsuya; Sudo, Katsuo; Takeuchi, Kentaro; Okita, Takatoshi; Kihara, Yoshiyuki

JAEA-Technology 2011-009, 100 Pages, 2011/06

JAEA-Technology-2011-009.pdf:32.59MB

Crystalline cellulose granulated to sizes from 70 to 100 micron was previously used as pore former (PF) to fabricate low density MOX pellets for MONJU. When sale of Avicel was discontinued, it became necessary to find a substitute PF. Then, small scale fabrication tests of MOX pellets with candidate PFs were conducted. Three candidate PFs, cellulose beads, CEOLUS and CELPHERE, were examined in the tests. The results are summarized below. (1) The CELPHERE gave MOX pellets with almost same density depression performance as pellets using Avicel, and standards deviation of the sintered densities of pellets was the smallest. (2) MOX pellets with CELPHERE had lower incidence of observable defects. (3) MOX pellets with CELPHERE had almost the same O/M as pellets with Avicel. (4) MOX pellets with CELPHERE had lower incidence of micro cracks. (5) The densification amount of pellets with CELPHERE was almost the same as that of pellets with Avicel. It was concluded CELPHERE was a suitable substitute for Avicel.

Journal Articles

Estimation of the paleostress field from the 3-D orientation distribution of microcracks and their geothermal conditions in the Toki Granite, central Japan

Takagi, Hideo*; Miwa, Shigenori*; Yokomizo, Yoshiyuki*; Nishijima, Kei*; Enjoji, Mamoru*; Mizuno, Takashi; Amano, Kenji

Chishitsugaku Zasshi, 114(7), p.321 - 335, 2008/07

Based on the 3-D orientations of intracrystalline healed, sealed and open extension microcracks in quartz grains in the Late Cretaceous Toki Granite, we discuss the paleostress field and the history of microcracking combining the microthermometry of fluid inclusions in healed microcracks and sealing material identification in sealed microcracks. Twenty one oriented samples are collected mainly from the DH-15 core (240-1000 mabh) drilled by Japan Atomic Energy Agency (JAEA) and additionally from five outcrops in the Tono region. 3-D orientations of healed microcracks indicate the $$sigma$$$$_{rm Hmax}$$ orientation of N-S to NW-SE in almost all sites, whereas those of sealed and open microcracks indicate the dominant $$sigma$$$$_{rm Hmax}$$ orientation of E-W. Two or three orthogonal sets of microcracks are common in both healed and sealed microcracks. The formation of these sets can be attributed to the switch of principal stress axis due to stress release just after the crack formation. Healed microcracks probably reflect more regional paleostress field because of consistency of the orientations than the case of sealed and open microcracks that show rather scattering orientations. N-S to NW-SE trending healed microcracks are formed around 60 Ma on the basis of K-Ar biotite ages of the Toki Granite and formation temperature (c. 300-400$$^{circ}$$C) of fluid inclusions estimated from microthermometry in the case of intrusion depth (3.5 km=100 MPa) of the Toki Granite. Thus the $$sigma$$$$_{rm Hmax}$$ orientation trended NW-SE after the restoration of clockwise rotation of SW Japan at c. 15 Ma. Following the healed microcrack formation, E-W trending high-angle sealed microcracks filled with carbonate mineral are formed. Open microcracks presumably formed at near-surface at the last stage of sealed microcrack formation after c. 20 Ma before the Mizunami Group deposited unconformably on the granite.

Journal Articles

Translational kinetic energy induced oxidation on Ti(0001) surfaces using a supersonic O$$_{2}$$ beam

Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Moritani, Kosuke*; Mizuno, Yoshiyuki*

Denki Gakkai Rombunshi, C, 127(2), p.140 - 145, 2007/02

The initial sticking probability of O$$_{2}$$ molecule on a Ti(0001)-1$$times$$1 surface at room temperature was measured as a function of translational kinetic energy by real-time photoelectron spectroscopy. The O 1s photoelectron spectra can be fitted well with three components A, B, and C, where the chemical shift of component B and C are +0.7 and +1.6 eV relative to the binding energy of component A (528.8 eV). Upon exposing to the O$$_{2}$$ beam, component A and C appear dominantly and component B grows with an incubation time, indicating that two kinds of chemical adsorption states are concerned with dissociative adsorption of O$$_{2}$$ molecule at the initial stage. The incident energy dependence of initial sticking probability shows quite different behaviours between component A and C: initial sticking probability of component C decreases monotonously with incident energy and is almost constant above 0.6 eV, while initial sticking probability of component A shows a rapid decrease followed by a gradual increase with a minimum at 0.5 eV and then decreases with two small maxima at 0.9 and 1.8 eV. The observed incident energy dependence of initial sticking probability for component A and C are discussed in terms of a trapping-mediated dissociative adsorption and a direct dissociative adsorption process.

Journal Articles

Real-time photoelectron spectroscopy for Nitridation at Ti(0001) surface using supersonic N$$_{2}$$ molecular beams

Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*

Shinku, 49(12), p.775 - 779, 2006/12

Nitridation on a Ti(0001)-1$$times$$1 surface using a supersonic N$$_{2}$$ molecular beam was investigated by real-time photoelectron spectroscopy to clarify the adsorption reaction dynamics of N$$_{2}$$ molecule on the Ti surface. In a whole N$$_{2}$$ dosage region examined, N 1s spectra can be fitted well with two chemically-shifted components, the binding energies of which are 396.9 and 396.6 eV, respectively. For both the components, the initial sticking probability S$$_{0}$$ shows a decrease with increasing incident energy in the overall trend, while has significant minima at 0.3 and 1.5 eV. Such incident energy dependences of S$$_{0}$$ suggest that the chemisorbed states are similarly caused by a trapping-mediated adsorption process through a physisorption state at lower incident energy than 0.3 eV and an activated adsorption process becomes dominant at higher incident energy than 0.3 eV.

JAEA Reports

Cause investigation and repair of breakage of catalyst dust filter on mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system (Contract research)

Morisaki, Norihiro; Hayashi, Koji; Inagaki, Yoshiyuki; Kato, Michio; Fujisaki, Katsuo*; Maeda, Yukimasa; Mizuno, Sadao*

JAERI-Tech 2005-009, 37 Pages, 2005/03

JAERI-Tech-2005-009.pdf:14.33MB

The breakage of the catalyst dust filter was found at the nozzle flange, which was welded onto the end plate of the filter, by the bubbling test using nitrogen gas of the mock-up model test facility. We investigated the cause of breakage and devised a repairing method. The cause of the breakage was the stress corrosion cracking (SCC) generated from the inside of the filter. The filter was repaired based on the following countermeasures such as reduction of condensed water in the filter, tensile stress and sensitization at welding joints. Furthermore, the inspection was carried out to investigate the structural integrity of the welding joints in the test facility of which structure, material and operating condition were similar to the filter. As the results, it was confirmed that the structural integrity was maintained.

JAEA Reports

Initial oxidation of Ti(0001) surfaces induced by supersonic oxygen molecular beams

Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*; Teraoka, Yuden; Yoshigoe, Akitaka; Moritani, Kosuke; Hachiue, Shunsuke

JAERI-Tech 2004-046, 25 Pages, 2004/06

JAERI-Tech-2004-046.pdf:2.51MB

We investigated the correlation between initial sticking coefficient and O$$_{2}$$ transitional kinetic energy to understand O$$_{2}$$ adsorption processes on the Ti(0001) surface via photoemission spectroscopy for O-1s and Ti-2p core levels using the surface reaction analysis apparatus, installed at the JAERI soft X-ray beamline BL23SU in the SPring-8. We observed the decrease of initial sticking coefficient of O$$_{2}$$ molecules on the Ti(0001) surface with increasing O$$_{2}$$ transitional kinetic energy. We concluded that the O$$_{2}$$ adsorption on the Ti(0001) surface proceeded by a trapping-mediated dissociative adsorption mechanism. The constant dependence of the initial sticking coefficient on incident angle of O$$_{2}$$ beams also suggested the propriety of the trapping-mediated surface reaction mechanism.

Journal Articles

Oxidation state during growth of very thin oxide on Ti(0001) surface

Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Moritani, Kosuke; Ogawa, Shuichi*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*

Shinku, 47(6), p.457 - 461, 2004/06

The oxidation reaction of Ti(0001) surface by oxygen molecules was observed by real-time in-situ photoemission spectroscopy using synchrotron radiation in the conditions of 400$$^{circ}$$C and 3.7$$times$$10$$^{-6}$$ Pa. The uptake curve of oxygen showed a plateau at the dose of 45-85 L and then increased again. This re-growth of oxide film was attributed to the drastic change of Ti oxidation state from TiO to TiO$$_{2}$$. Consequently, the characteristic change of the uptake curve was caused by the oxidation state change of Ti atoms.

Journal Articles

In-situ observation of oxidation of Ti(0001) surface by real-time photoelectron spectroscopy using synchrotron radiation

Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*

Hyomen Kagaku, 24(8), p.500 - 508, 2003/08

Temperature dependence of the initial oxidation kinetics of Ti(0001) surface was investigated by low energy electron diffraction (LEED) and real-time photoelectron spectroscopy. The LEED observation revealed that the oxide layers grew epitaxially. From the oxygen uptake curve, it was clarified that oxigen diffusion was significantly enhanced by surface temperature and the oxide layers thickness reached to 7 nm at 400$$^{circ}$$C. From Ti-2p photoelectron spectroscopy, TiO$$_{2}$$ was predominant at the subsurface while TiO and Ti$$_{2}$$O$$_{3}$$ components were also observed at the interface.

Journal Articles

Real-time monitoring of oxidation on the Ti(0001) surface by synchrotron radiation photoelectron spectroscopy and RHEED-AES

Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Yamauchi, Yasuhiro*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*

Applied Surface Science, 216(1-4), p.395 - 401, 2003/06

 Times Cited Count:18 Percentile:65.47(Chemistry, Physical)

Real-time in-situ observation using photoelectron spectroscopy for elementary processes of Ti(0001) oxidation by O$$_{2}$$ molecules has been performed at the surface reaction analysis apparatus installed at the BL23SU in the SPring-8. And the real-time observation has been also performed by RHEED-AES methods at Tohoku University. The partial pressure region of oxygen was from 2x10$$^{-7}$$ Torr to 8x10$$^{-8}$$ Torr. The surface temperature was 473 K and 673 K. The variation from clean Ti surface toward TiO$$_{2}$$ was comfirmed by observation of Ti-2p and O-1s photoelectron spectra. Reflected electron intensity and O-KLL Auger electron intensity oscillated in the RHEED-AES measurements. These facts revealed that the surface morphological change of the oxidized Ti(0001) surface was associated not only with a disappearance of the surface metallic layer but also with a change of the oxidation state.

Journal Articles

Time-resolved photoelectron spectroscopy of oxidation on the Ti(0001) surface

Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*

Nuclear Instruments and Methods in Physics Research B, 200, p.376 - 381, 2003/01

 Times Cited Count:10 Percentile:58.26(Instruments & Instrumentation)

no abstracts in English

Journal Articles

A Promising Gas-Cooled Fast Reactor Concept and its R&D Plan

Konomura, Mamoru; SAIGUSA, Toshiie; Mizuno, Tomoyasu; OHKUBO, Yoshiyuki*

Fast Spectrum Reactors, 0 Pages, 2003/00

In Feasibility Studies on Commercialized Fast Reactor (FR) Systems, examining about the subject of three gas cooled FR concepts, (1) carbon dioxide cooled FR using pin type fuel, (2) helium cooled FR using pin type fuel, (3) helium cooled FR using coated particle fuel, a promising concept has been selected from three concepts. From a viewpoint of economic competitiveness and ensuring safety, etc, "helium cooled FR using coated particle fuel" has been selected as a promising concept of gas cooled FR. About fuel assembly concept of helium cooled FR using coated particle fuel, block type vertical flow cooling concept with 2nd boundaries was also examined, other than horizontal flow cooling concept with directly cooling system. About selected helium cooled FR using coated particle fuel, it drew up R&D plan about the most important R&D items influencing on the feasibility of the design concept.

Oral presentation

Real-time in-situ photoelectron spectroscopy of surface temperature dependence for Ti(0001) nitridation reaction processes

Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*

no journal, , 

Nitridation reactions of a Ti(0001) surface, induced by supersonic nitrogen molecular beams, were analysed via real-time in-situ photoemission spectroscopy with synchrotron radiation. Surface temperature dependence of nitrogen uptake curves and nitrided chemical bonding states were investigated. The incident energy range of supersonic nitrogen molecular beams was from 0.03 eV to 1.99 eV. Surface temperature was set at 27$$^{circ}$$C, 200$$^{circ}$$C, and 400$$^{circ}$$C. The photon energy of synchrotron radiation was 668 eV. A photoemission spectrum of N1s peak could be recorded successfully with a period of 26s. Although the N1s photoemission peak was composed of 2 components at 27$$^{circ}$$C and 200$$^{circ}$$C, an additional conponent was needed at 400$$^{circ}$$C.

Oral presentation

Nitridation reaction dynamics on Ti(0001) surfaces using a supersonic nitrogen molecular beam

Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*

no journal, , 

In order to study adsorption reaction dynamics of nitrogen molecules at Ti surfaces, Ti(0001) nitridation processes via supersonic nitrogen molecular beams were observed by real-time photoelectron spectroscopy. Incident energy dependence of initial sticking probability was investigated for each adsorption state of nitrogen molecules. The N1s photoemission peak consists of two components. The incident energy dependence of initial sticking probability was obtained from adsorption uptake curves for each component. The two components revealed almost same tendency. It was indicated that dissociative adsorption via a physical adsorption state was a major process in the incident energy less than 0.3 eV, and direct adsorption took place mainly in the incident energy larger than 0.3 eV.

Oral presentation

3-D directional distribution of microcracks in the Toki granite, and estimation of the paleostress field and geothermal condition

Miwa, Shigenori*; Takagi, Hideo*; Nishijima, Kei*; Yokomizo, Yoshiyuki*; Enjoji, Mamoru*; Mizuno, Takashi

no journal, , 

no abstracts in English

Oral presentation

Oxidation reaction kinetics on Ti(0001) surface studied by real-time monitoring methods of XPS, UPS, and RHEED combined with AES

Takakuwa, Yuji*; Ogawa, Shuichi*; Ohira, Masayuki*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Yamauchi, Yasuhiro*; Homma, Teiichi*

no journal, , 

Oxidation processes of Ti(0001)-1$$times$$1 clean surface were analyzed by real-time monitoring using a variety of surface analysis methods of XPS, UPS, and AES/RHEED. Following conclusions were obtained by these observations. Oxide layer grows epitaxially at the Ti(0001) surface with a $$sqrt{3}$$$$times$$$$sqrt{3}$$ structure. Surface roughness changes periodically. The period is consistent with that of work function. Low oxidation state (TiO) plays a dominant role in the dissociative adsorption of oxygen molecules. The oxide layer decomposes easily at surface temperature over 673 K. The TiO$$_{2}$$ structure reduces to TiO during thermal decomposition.

Oral presentation

Conceptual design toward the commercial reactor of JSFR, 3; Fast reactor core and fuel concepts for high burnup

Kaito, Takeji; Otsuka, Satoshi; Inoue, Masaki; Asayama, Tai; Okubo, Tsutomu; Mizuno, Tomoyasu; Okubo, Yoshiyuki*; Kotake, Shoji*

no journal, , 

An innovative core and fuel concept of Japan Sodium-cooled Fast Reactor (JSFR) is aiming at achieving as high burn-up as 150 GWd/t of average discharge burn-up to improve its economical competitiveness. A candidate of innovative technology to achieve such high burn-up is oxide-dispersion-strengthened (ODS) ferritic cladding material with both excellent irradiation resistance and high strength at elevated temperature. This paper reports the result of applicability study of the innovative technologies for the JSFR core.

Oral presentation

Feasibility study on fabrication of MOX fuel pellet by blending recycle powder with granulated powder

Mizuno, Mineo; Sudo, Katsuo; Takeuchi, Kentaro; Okita, Takatoshi; Kihara, Yoshiyuki

no journal, , 

The short process is considered to be a main concept which has high feasibility in Fast Reactor Cycle Technology Development (FaCT). In this study, a small-scale fabrication test was carried out to investigate characteristic of MOX pellet made of granulated MOX powder blended with dry-route recycle powder, for the first time, as a basic test concern with the short process. As the results, it was found that the sintered density of the pellet clearly depends on the preparing conditions and content of recycle powder. The results is intended to be utilized in the investigation of engineering-scale test conditions.

Oral presentation

Including the muon nuclear reaction model into the PHITS code

Noda, Shusaku; Hashimoto, Shintaro; Sato, Tatsuhiko; Niita, Koji*; Mizuno, Yoshiyuki*

no journal, , 

The authors has improve the photonuclear reaction model in the PHITS code. Photon-induced pion production process is newly included in PHITS in order to reproduce the photonuclear reaction caused by virtual photons generated from muon nuclear interaction. PHITS with the improved photonuclear reaction model can reproduce the experimental reults to some accuracy. Moreover it is planned to include the virtual photon generation model. Using the phonuclear reaction model and the muon interaction model, PHITS can be to handle the muon interation.

Oral presentation

Current status of SmART cycle project in JAEA

Watanabe, So; Sano, Yuichi; Kofuji, Hirohide; Takeuchi, Masayuki; Tanaka, Kosuke; Koizumi, Tsutomu; Mizuno, Tomoyasu; Kihara, Yoshiyuki

no journal, , 

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