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JAEA Reports

Screening test of relays used under pressurized sulfur hexafluoride (SF$$_{6}$$)

Kutsukake, Kenichi; Matsuda, Makoto; Hanashima, Susumu; Obara, Kenjiro*

JAEA-Technology 2007-068, 52 Pages, 2008/01

JAEA-Technology-2007-068.pdf:3.02MB

Many measurement and control equipment is installed inside of a high voltage terminal of the JAEA-Tokai tandem accelerator and operated under pressurized sulfur hexafluoride (SF$$_{6}$$) of 0.5 MPa. This screening test has been carried out to select a relay, which is usable under the SF$$_{6}$$ for turn on and off a power supply of the devices, from commercial relays used in the atmospheric condition. Four kinds of relay were tested: electromechanical relay (EMR), magnet contactor (MAG), solid-state relay (SSR) and hybrid relay (HYB). Temperature of the relay, change of appearance of the relay including contact surface using the SEM and EDS were measured and observed. The EMR and the MAG showed irregular contact because of the sulfide or fluoride, and these compounds which are formed by chemical reaction between metals and sulfur or hydrogen fluoride due to dissociation of SF$$_{6}$$ in electric arcs. Solid-state relay and hybrid relay are available in the pressurized SF$$_{6}$$ of 0.5 MPa.

JAEA Reports

Study on assembly techniques and procedures for ITER tokamak device

Obara, Kenjiro; Kakudate, Satoshi; Shibanuma, Kiyoshi; Sago, Hiromi*; Ue, Koichi*; Shimizu, Katsusuke*; Onozuka, Masanori*

JAEA-Technology 2006-034, 85 Pages, 2006/06

JAEA-Technology-2006-034.pdf:9.18MB

The International Thermonuclear Experimental Reactor (ITER) tokamak is composed of many kinds of components. The dimensions and weight of the respective components are around a few ten-meters and several hundred-tons. In addition, the whole tokamak assembly, which are composed of these components, are roughly estimated, 26 m in diameter, 18 m in height and over 16,500 tons in total weight. On the other hand, as for positioning and assembly tolerances of these components are required to be a high accuracy of $$pm$$3mm in spite of large size and heavy weight. The assembly procedures and techniques of the ITER tokamak are therefore studied, taking account of the tolerance requirements. Based on the above background, the assembly procedures and techniques, which are able to assemble the tokamak with high accuracy, are described in the present report. The following newly developed tokamak assembly procedures and techniques, jigs and tools for assembly and metrology concept based on the available knowledge and experiences of the installation of the large components, in order to improve the IT (International Team) design toward the more realistic one. As a result, we show the realistic tokamak assembly procedures and techniques to be able to assemble the large and heavy ITER tokamak with high accuracy. (1)Assembly and alignment of the toroidal field coil with high accuracy. (2)Simplification of the assembly procedures, and the jigs/tools and procedures to reduce the misalignment. (3)Assembly procedures and techniques for the vacuum vessel to reduce the weld distortion. (4)Supporting procedures and techniques of the vacuum vessel sector to prevent the toridal field coil from the deformation due to the dead weight of the vacuum vessel sector. (5)Datum points and lines for the required positions and assembly tolerances during tokamak assembly.

JAEA Reports

Continuous running test of radiation resistance motor driving equipment under high gamma ray irradiation

Obara, Kenjiro; Kakudate, Satoshi; Yagi, Toshiaki; Morishita, Norio; Shibanuma, Kiyoshi

JAEA-Technology 2006-023, 38 Pages, 2006/03

JAEA-Technology-2006-023.pdf:5.21MB

The components in the vacuum vessel of ITER (International Thermonuclear Experimental Reactor), e.g. blanket and divertor, are replaced using the dedicated remote handling systems. The environment conditions inside the vacuum vessel during the operation are temperature of 50$$^{circ}$$C, gamma ray radiation and air or inert gas atmosphere at 1 atm. ; therefore multiple elements are required as durability of the remote handling systems. In addition, the remote handling system it is desired to be able to operate over a long time. The radiation resistance motor driving equipment, which comprises parts with different radiation resistance levels, was designed simulating mechanisms of the ITER remote handling systems. The equipment being the servomotor, turns the weight (dummy load) of 8 kgf and controls, and continuous running test under high gamma ray irradiation was started from March, 2000. Irradiation conditions on the test were the dose rate of 3.6 kGy/h, the target accumulation dose of 30 MGy at the minimum. The irradiation test was performed two stages which was divided by overhaul of the equipment. The achieved accumulation dose and running time in these stages were approximately 47.6 MGy/13,200 hours and 23.9 MGy/6,640 hours, respectively. As a result, it has been confirmed that sufficient radiation resistance of the equipment, which is required from the latest dose rate of 0.5 kGy/h inside the vacuum vessel was achieved. In this report, we describe design conditions of the equipment and the results of the 1st and 2nd irradiation tests and the overhaul after the 1st irradiation test.

JAEA Reports

Development of colored alumilite dosimeter

Obara, Kenjiro; Yagi, Toshiaki; Yokoo, Noriko*; Shibanuma, Kiyoshi

JAERI-Tech 2003-035, 107 Pages, 2003/03

JAERI-Tech-2003-035.pdf:9.45MB

no abstracts in English

Journal Articles

Exposure to tritiated moisture and decontamination of components for ITER remote maintenance equipment

Higashijima, Takeshi*; Obara, Kenjiro; Shibanuma, Kiyoshi; Koizumi, Koichi; Kobayashi, Kazuhiro; Oya, Yasuhisa; Shu, Wataru; Hayashi, Takumi; Nishi, Masataka

Fusion Science and Technology, 41(3), p.731 - 735, 2002/05

no abstracts in English

JAEA Reports

Development of fabrication technology for ITER vacuum vessel

Nakahira, Masataka; Shibanuma, Kiyoshi; Kajiura, Soji*; Shibui, Masanao*; Koizumi, Koichi; Takeda, Nobukazu; Kakudate, Satoshi; Taguchi, Ko*; Oka, Kiyoshi; Obara, Kenjiro; et al.

JAERI-Tech 2002-029, 27 Pages, 2002/03

JAERI-Tech-2002-029.pdf:2.04MB

The ITER vacuum vessel (VV) R&D has progressed with the international collaborative efforts by the Japan, Russia and US Parties during the Engineering Design Activities (EDA). Fabrication and testing of a full-scale VV sector model and a port extension have yielded critical information on the fabrication and assembly technologies of the vacuum vessel, magnitude of welding distortions, dimensional accuracy and achievable tolerances during sector fabrication and field assembly. In particular, the dimensional tolerances of $$pm$$3 mm for VV sector fabrication and $$pm$$10 mm for VV sector field assembly have been achieved and satisfied the requirements of $$pm$$5 mm and $$pm$$20 mm, respectively. Also, the basic feasibility of the remote welding robot has been demonstrated. This report presents detailed fabrication and assembly technologies such as welding technology applicable to the thick wall without large distortion, field joint welding technology between sectors and remote welding technology through the VV R&D project.

Journal Articles

Development of new dosimeter using colored alumilite fading

Obara, Kenjiro

Genshiryoku eye, 48(2), p.46 - 48, 2002/02

no abstracts in English

Journal Articles

Mere look to know an accumulation, development colored alumilite dosimeter

Obara, Kenjiro

Hoshasen To Sangyo, (92), p.56 - 60, 2001/12

no abstracts in English

Journal Articles

Decontamination of candidate materials for ITER remote handling equipment exposed to tritiated moisture

Oya, Yasuhisa; Kobayashi, Kazuhiro; Shu, Wataru; Hayashi, Takumi; Ohira, Shigeru; Nakamura, Hirofumi; Iwai, Yasunori; Nishi, Masataka; Higashijima, Takeshi*; Obara, Kenjiro; et al.

Fusion Technology, 39(2-Part2), p.1023 - 1027, 2001/03

no abstracts in English

Journal Articles

Mechanical characteristics and position control of vehicle/manipulator for ITER blanket remote maintenance

Kakudate, Satoshi; Oka, Kiyoshi; Yoshimi, Takashi*; Taguchi, Ko*; Nakahira, Masataka; Takeda, Nobukazu; Shibanuma, Kiyoshi; Obara, Kenjiro; Tada, Eisuke; Matsumoto, Yasuhiro*; et al.

Fusion Engineering and Design, 51-52(1-4), p.993 - 999, 2000/11

 Times Cited Count:9 Percentile:55.69(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Development of colored alumilite dosimeter for high radiation use

Obara, Kenjiro; Tada, Eisuke; Koizumi, Koichi; Yagi, Toshiaki; Morita, Yosuke

Proceedings of Radiation Effects on Components and Systems (RADECS 2000), p.214 - 218, 2000/09

no abstracts in English

JAEA Reports

Development of radiation-hard electric connector with ball bearing for in-vessel remote maintenance equipment of ITER, 2

*; Obara, Kenjiro; Tada, Eisuke; Morita, Yosuke; Yagi, Toshiaki; *

JAERI-Tech 99-029, 36 Pages, 1999/03

JAERI-Tech-99-029.pdf:3.25MB

no abstracts in English

JAEA Reports

Design and development of in-vessel viewing periscope for ITER (International Thermonuclear Experimental Reactor)

Obara, Kenjiro; Kakudate, Satoshi; *; Shibanuma, Kiyoshi; Tada, Eisuke

JAERI-Tech 99-009, 83 Pages, 1999/02

JAERI-Tech-99-009.pdf:5.99MB

no abstracts in English

JAEA Reports

High $$gamma$$-rays irradiation tests of critical components for ITER (International Thermonulear Experimental Reactor) in-vessel remote handling system

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; *; *; Koizumi, Koichi; Shibanuma, Kiyoshi; Yagi, Toshiaki; Morita, Yosuke; ; et al.

JAERI-Tech 99-003, 312 Pages, 1999/02

[This article is unavailable to download the full text due to various reasons.]

Journal Articles

High radiation-resistant image fiber for remote maintenance equipment of ITER

Morita, Yosuke; Obara, Kenjiro

Denki Gakkai Yuden, Zetsuen Zairyo Kenkyukai Shiryo; DEI-99-18, p.55 - 58, 1999/02

no abstracts in English

Journal Articles

Development of 15-m-long radiation hard periscope for ITER in-vessel viewing

Obara, Kenjiro; *; Kakudate, Satoshi; Oka, Kiyoshi; Nakahira, Masataka; Morita, Yosuke; *; *; Takeda, Nobukazu; Takahashi, Hiroyuki*; et al.

Fusion Engineering and Design, 42, p.501 - 509, 1998/00

 Times Cited Count:3 Percentile:32.94(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Development of radiation hardness components for ITER remote maintenance

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; *; Yagi, Toshiaki; Morita, Yosuke

J. Robot. Mechatron., 10(2), p.121 - 132, 1998/00

no abstracts in English

Journal Articles

Development of ITER in-vessel viewing and metrology systems

Obara, Kenjiro; Kakudate, Satoshi; Nakahira, Masataka; *

J. Robot. Mechatron., 10(2), p.96 - 103, 1998/00

no abstracts in English

Journal Articles

Development of bore tools for blanket cooling pipe connection in ITER

*; Oka, Kiyoshi; Kakudate, Satoshi; Obara, Kenjiro; *; Tada, Eisuke; A.Tesini*; Shibanuma, Kiyoshi; R.Haange*

Proc. of 17th IEEE/NPSS Symposium Fusion Engineering (SOFE'97), 2, p.921 - 924, 1998/00

no abstracts in English

JAEA Reports

Development of radiation-hard electric connector with ball bearing for in-vessel remote maintenance equipment of ITER

*; Obara, Kenjiro; Tada, Eisuke; Morita, Yosuke; Yagi, Toshiaki; *; *

JAERI-Tech 97-065, 62 Pages, 1997/12

JAERI-Tech-97-065.pdf:3.6MB

no abstracts in English

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