Protonic conduction, crystal and electronic structures of LaBaGaMgO

Hamao, Naoki*; Kitamura, Naoto*; Ito, Takanori*; Igawa, Naoki; Idemoto, Yasushi*; Daido, Hiroyuki; Kaku, Masanori*; Kubodera, Masakazu*

Solid State Ionics, 253, p.123 - 129, 2013/12

https://doi.org/10.1016/j.ssi.2013.09.021

LaBaGaMgO which is one of the candidates for solid electrolyte of solid oxide fuel cell was synthesized by means of a conventional solid-state reaction, and investigated by conductivity measurements, the Rietveld and maximum entropy method analyses using neutron and synchrotron X-ray diffraction data. Conductivity measurements indicated that simultaneous Ba and Mg substitutions for LaBaGaO were effective way to improve the protonic conductivity. From the Rietveld and maximum entropy method analyses, it was confirmed that LaBaGaMgO kept the same crystal structure as LaBaGaO even at elevated temperature, i.e. 1000 K, and that protons existed around the O3 site and formed hydrogen bonds. It is also found that oxygens in LaBaGaO-based samples formed Ga-O tetrahedra, and the bonding strength was varied by the partial substitutions.

Beam loss occurred at DTL cavity in J-PARC linac

Miura, Akihiko; Miyao, Tomoaki*; Ito, Takashi; Hirano, Koichiro; Nammo, Kesao*; Maruta, Tomofumi; Tamura, Jun; Ikegami, Masanori*; Naito, Fujio*

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.653 - 655, 2013/08

http://www.pasj.jp/web_publish/pasj9/proceedings/PDF/WEPS/WEPS094.pdf

The beam operation of J-PARC linac was suspended until December 2011 due to the damage by the Tohoku earthquake in March 2011. After resumed the operations, we measured the residual radiation along with the beam line during a short interval. Because the higher residual radiation was detected at the surface of drift tube linac (DTL) cavity by radiation survey, we installed the scintillation beam loss monitors (BLM) at the points where the higher radiation was detected to understand the cause of the radiation. Even the DTL section is low energy part of the linac, fine structure of the beam loss was observed by the scintillation BLM. And we measured the beam loss occurred at the DTL with the parameters of beam orbit and cavity settings. Also, the BLM is employed for the linac tuning. In this paper, the result of the radiation measurement and beam loss signals obtained by the scintillation BLMs are presented.

Beam loss reduction by the beam duct realignment in the J-PARC linac beam transport line

Tamura, Jun; Ao, Hiroyuki; Asano, Hiroyuki; Ikegami, Masanori*; Maruta, Tomofumi; Miura, Akihiko; Morishita, Takatoshi; Oguri, Hidetomo; Ouchi, Nobuo; Sawabe, Yuki*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.377 - 380, 2013/08

http://www.pasj.jp/web_publish/pasj9/proceedings/PDF/WEPS/WEPS013.pdf

In the J-PARC linac, almost all the cavities and magnets have been precisely aligned because the accelerator tunnel has been deformed by the 2011 Tohoku Earthquake. In the beam transport line called MEBT2 and A0BT at the downstream of the drift tube linac, the beam duct has been roughly aligned after the precise alignment of the quadruple doublets. During the first beam operation after the earthquake, remarkable beam loss and residual radiation have been recognized at the MEBT2 and A0BT. As the result of the duct position measurement, the misalignement including over 10 mm shift from the beam axis was found. By conducting the beam duct realignment, the beam loss and the residual radiation were successfully decreased. In this paper, the procedure of the beam duct alignment and the beam loss due to the misalignment are described.

Development of simulator for materials testing reactors; Model overview

Kollryd, T.*; Romas, A.*; Porter-Peden, M.*; Takemoto, Noriyuki; Kimura, Nobuaki; Ooka, Makoto; Kaminaga, Masanori; Ishitsuka, Tatsuo*; Tamura, Kazuo*

Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10

http://www.murr.missouri.edu/ismtr/papercall/Papers/GSE%20Power/Kollryd_T=PAPER_Dev%20of%20Simulator%20for%20MTRs-Model%20Overview.pdf

A simulator for materials testing reactors has been developed to be utilized for human resource development with an advancement of technology in mind. The simulator is designed based on the JMTR, and the reactor core is modeled with REMARK, in which a 3-dimensional, 4-energy group, time dependent, diffusion theory model is applied. The thermo-hydraulic properties in the reactor vessel are modeled using RELAP5-HD, which is the real-time version of RELAP5-3D code. REMARK interacts with the RELAP5-HD thermal hydraulic model by providing power to the moderator. The RELAP5-HD model, in return, provides thermal hydraulic feedback to the REMARK model. For the primary and secondary cooling loops, main heat exchangers, purification system and cooling towers, the 2-phase, 6-equation matrix solution modeling tool JTopmeret is used. The high fidelity level of modern simulators is not only a valuable tool for human resource training, but also an analysis tool for safety in normal/transient/accident conditions of materials testing reactors.

Improvements in plastic enclosure system for glovebox decommissioning

Watahiki, Masatoshi; Akai, Masanori; Nakai, Koji; Iemura, Keisuke; Yoshino, Masanori*; Hirano, Hiroshi*; Kitamura, Akihiro; Suzuki, Kazunori

Nihon Genshiryoku Gakkai Wabun Rombunshi, 11(1), p.101 - 109, 2012/02

https://doi.org/10.3327/taesj.J10.037

Gloveboxes used for plutonium fuel development and fabrication are eventually dismantled for replacement or decommissioning. Since equipment interior and the inner surface of gloveboxes are contaminated in radioactive materials, glovebox dismantling work is performed by workers wearing an air fed suit with mechanical tools in a plastic enclosure system to control the spread of contamination. Various improvements of enclosure system are implemented including modification of the rooms to decontaminate and undress the air fed suit and introduction of inflammable filter and safety film near the size reduction workspace against fire. We describe the countermeasures deployed in the enclosure system against potential hazards and how these devices work in the real dismantling activities.

Study on Advanced Structural Design for Commercialized Fast Breeder Reactors

Morishita, Masaki; Kitamura, Seiji; Takahashi, Kenji; Inoue, Kazuhiko; Kida, Masanori; Moro, Satoshi*; Kato, Asao*; Fushimi, Minoru*

JNC TY9400 2004-028, 921 Pages, 2004/11

Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Power Company (JAPC) launched joint research programs on structural design and three-dimensional seismic isolation technologies, as part of the supporting R&D activities for the feasibility studies on commercialized fast breeder reactor cycle systems. A research project by JAPC under the auspices of the Ministry of Economy, Trade, and Industry (METI) with technical support by JNC is included in this joint study. This report contains the results of the research on the structural design technology. The research scope was identified as (1) Study on Developing Program, (2) Study on 3-dimentional Entire Building Base Isolation System, and (3) Study on Vertical Isolation System for Main Equipment, and the results of this year's studies are summarized as follows. (1) Study on Developing Program -Performance Requirements for 3-dimensional Isolation Devices "The behavior of a three-dimensional isolated reactor building" and "amenity under the strong wind load" were studied in order to set up performance requirements for the three-dimensional isolation system. Consequently, it was proved for the former subject that the structure of horizontal base-dimensional isolated building was applicable to 3-D isolated building and for the latter that amenity of the operator in the 3-D isolated reactor building is not affected under the strong wind. -Development Targets and Schedules for Three-dimensional Isolation Deviece In order to select the development candidate of the three dimensional isolation devices, "evaluation items and criteria" and "technical guideline on seismic three-dimensional isolation system" were studied. For the former subject, detailed requirements to the component in the reactor building were studied based on the 2002 fiscal year result and embodied.(2) Study on 3-dimentional Entire Building Base Isolation System -The 3 system concepts nominated on 2001, "Hydraulic system", "Fiber reinforced air sp

Study on Advanced Structural Design for Commercialized Fast Breeder Reactors

Morishita, Masaki; Kitamura, Seiji; Inoue, Kazuhiko; Kida, Masanori; Moro, Satoshi; Kato, Asao; Fushimi, Minoru*

JNC TY9400 2003-009, 682 Pages, 2003/05

JNC-TY9400-2003-009.pdf:35.1MB

Japan Nuclear Cycle Development Institute(JNC) and Japan Atomic Power Company (JAPC) launched joint research programs on structural design and three-dimensional seismic isolation technologies,as part of the supporting R&D activities for the feasibility studies on commercialized fast breeder reactor cycle systems. A research project by JAPC under the auspices of the Ministry of Economy,Trade,and Industry (METI) with technical support by JNC is included in this joint study. This report contains the results of the research on the structural design technology. The research scope was identified as (1) Study on Developing Program,(2) Study on 3-dimentional Entire Building Base Isolation System,and (3) Study on Vertical Isolation System for Main Equipment, and the results of this year's studies are summarized as follows.

In situ EXAFS study on GeS glass under high-pressure

Miyauchi, Koichi*; Qiu, J.*; Shojiya, Masanori*; Kawamoto, Yoji*; Kitamura, Naoyuki*; Fukumi, Kohei*; Katayama, Yoshinori; Nishihata, Yasuo

Solid State Communications, 124(5-6), p.189 - 193, 2002/10

https://doi.org/10.1016/S0038-1098(02)00489-1

A GeS glass was compressed up to 8 GPa at room temperature, heated up to 270 C under 8 GPa and then decompressed to ambient pressure at room temperature, using a large volume high-pressure apparatus. The local structural-changes around Ge were examined by means of EXAFS method. The Ge-S bond length became monotonously short with increasing applied-pressure up to 8 GPa at room temperature. When the specimen was heated to 270 C under 8 GPa, however, the vond length became slightly long. The elongated bond lengthe was almost kept even after the temperature was descended to room tempertature. In decompression process, the bond length became gradually long with releasing applied-pressure down to 2 GPa, following a change in compression process. Below 2 GPa, however, the Ge-S bond length was largely elongated, being lnger than the initial one. No significant change of coordination number was found in the compression and decompression processes up to 8 GPa. This change canbe explained by a combined effect of elastic and inelastic structural-changes.

MPI performance measurement on nodes of the earth simulator

Uehara, Hitoshi; Tamura, Masanori; Yokokawa, Mitsuo

Hai Pafomansu Komputingu To Keisan Kagaku Shimpojium (HPCS2002) Rombunshu, p.73 - 80, 2002/01

The Earth Simulator is an ultra high-speed supercomputer which is developed now for global environment change simulations. For achieving high performance computing on large scale distributed memory parallel computer such as the Earth Simulator, an optimization of communication processings in user applications is required, and the optimization needs an evaluation for performances of communication methods. In the Earth Simulator, Message Passing Interface (MPI) is supported as the communication method. We evaluated performances of the MPI-1/MPI-2 functions on the Earth Simulator in detail using MBL which we developed.

X-ray diffraction technique in energy-dispersive mode at SPring-8 for fluids at high temperatures and high pressures

Tamura, Kozaburo*; Inui, Masanori*; Funakoshi, Kenichi*; Utsumi, Wataru

Nuclear Instruments and Methods in Physics Research A, 467-468(Part2), p.1065 - 1068, 2001/07

https://doi.org/10.1016/S0168-9002(01)00724-0

no abstracts in English