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JAEA Reports

Maintenance of helium refrigerator/liquefier system in ITER CS Model Coil Test Facility

Ebisawa, Noboru; Kiuchi, Shigeki*; Kikuchi, Katsumi*; Kawano, Katsumi; Isono, Takaaki

JAEA-Testing 2014-003, 37 Pages, 2015/03

JAEA-Testing-2014-003.pdf:11.7MB

Objective of the ITER CS Model Coil Test Facility is to evaluate a large scale superconducting conductor for fusion using the Central Solenoid (CS) Model Coil, which can generate a 13-T magnetic field in the inner bore with a 1.5m diameter. The facility is composed of a helium refrigerator / liquefier system, a DC power supply system, a vacuum system and a data acquisition system. This report describes that maintenance of the helium refrigerator / liquefier system since the Great East Japan Earthquake in March 2011 until the first operation after the earthquake in December 2012.

Journal Articles

Examination of Japanese mass-produced Nb$$_3$$Sn conductors for ITER toroidal field coils

Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Takahashi, Yoshikazu; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Ebisawa, Noboru; et al.

IEEE Transactions on Applied Superconductivity, 22(3), p.4804804_1 - 4804804_4, 2012/06

 Times Cited Count:17 Percentile:65.56(Engineering, Electrical & Electronic)

no abstracts in English

Journal Articles

Pressure drop characteristic of the ITER cable-in-conduit conductor

Hamada, Kazuya; Kawano, Katsumi; Ebisawa, Noboru; Nakajima, Hideo; Yano, Yoshitaka*; Yamaguchi, Takanori*

Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.559 - 562, 2012/05

The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field Coil conductors and 100% of Central Solenoid Conductor as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is composed of 900 Nb$$_{3}$$Sn superconducting strands and 522 Cu strands protected by a circular sheath tube (jacket) with an outer diameter of 43.7 mm. The TF conductor has a central spiral cooling tube and a coolant flows into the cable space and the central channel in parallel. JAEA has measured a pressure drop characteristic of more than 20 TF conductors having different length using nitrogen gas at room temperature as a part of acceptance test. The measurement results are normalized to friction factor as a function of Reynolds number to check the difference of each other. The results show the normalized pressure drop characteristic is same among conductors. This is one of evidences that TF conductor is manufactured uniformly.

Journal Articles

Development of manufacturing technologies for ITER Toroidal Field coil conductors

Hamada, Kazuya; Takahashi, Yoshikazu; Nabara, Yoshihiro; Kawano, Katsumi; Ebisawa, Noboru; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Saito, Toru*; Nakajima, Hideo; Matsuda, Hidemitsu*; et al.

Teion Kogaku, 47(3), p.153 - 159, 2012/03

The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA has constructed newly conductor manufacturing facility. Prior to starting conductor, JAEA manufactured a 760-m long Cu dummy conductor as process qualification of dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.

Journal Articles

Fracture estimation method for pipe with multiple circumferential surface flaws subjected to bending

Li, Y.*; Sugino, Hideharu*; Hasegawa, Kunio*; Onizawa, Kunio; Doi, Hiroaki*; Ebisawa, Katsumi*

Nihon Kikai Gakkai Rombunshu, A, 75(749), p.56 - 63, 2009/01

When a flaw is detected in a stainless steel pipe during in-service inspection, the limit load criterion given in the standards such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI can be applied to evaluate the integrity of the pipe. However, in the present standards, the limit load criterion is only provided for the case of single flaw, although multiple flaws such as stress corrosion cracking have been detected in the same circumferential cross section in a pipe. In this paper, a fracture estimation method is proposed based on the limit load criterion for multiple independent circumferential surface flaws with arbitrary number and distribution, to evaluate the integrity of the pipe in a rational way. Several numerical examples are given to show the validity of this method.

JAEA Reports

Modification of the drift ducts reionization loss estimation for JT-60U NBI

Kawai, Mikito; Akino, Noboru; Ikeda, Yoshitaka; Ebisawa, Noboru; Honda, Atsushi; Kazawa, Minoru; Kikuchi, Katsumi; Mogaki, Kazuhiko; Noto, Katsuya; Oshima, Katsumi; et al.

JAEA-Technology 2008-069, 32 Pages, 2008/10

JAEA-Technology-2008-069.pdf:6.75MB

The neutral beam injection system for JT-60U consists of positive-ion based type(P-NBI) and negative-ion based type(N-NBI). The reionization losses of neutral beams in the drift ducts of both P-NBI and N-NBI are estimated using the data of ambient pressure and gas flow rate into the beamlines. This system was not enough to obtain detail injection power for a long pulse operation. Modifications of the system to obtain reionization loss for a long pulse operation have been conducted. The new system has a capability to measure the pressures of drift duct during operation. The system can calculate the reionization loss automatically during the pulse from the measured pressure. More acurate injection power can be obtained by this new system.

Journal Articles

Recent R&D activities of negative-ion-based ion source for JT-60SA

Ikeda, Yoshitaka; Hanada, Masaya; Kamada, Masaki; Kobayashi, Kaoru; Umeda, Naotaka; Akino, Noboru; Ebisawa, Noboru; Inoue, Takashi; Honda, Atsushi; Kawai, Mikito; et al.

IEEE Transactions on Plasma Science, 36(4), p.1519 - 1529, 2008/08

 Times Cited Count:11 Percentile:41.29(Physics, Fluids & Plasmas)

The JT-60SA N-NBI system is required to inject 10 MW for 100 s at 500 keV. Three key issues should be solved for the JT-60SA N-NBI ion source. One is to improve the voltage holding capability. Recent R&D tests suggested that the accelerator with a large area of grids may need a high margin in the design of electric field and a long time for conditioning. The second issue is to reduce the grid power loading. It was found that some beamlets were strongly deflected due to beamlet-beamlet interaction and strike on the grounded grid. The grids are to be designed by taking account of beamlet-beamlet interaction in three-dimensional simulation. Third is to maintain the D- production for 100 s. A simple cooling structure is proposed for the active cooled plasma grid, where a key is the temperature gradient on the plasma grid for uniform D- production. The modified N-NBI ion source will start on JT-60SA in 2015.

JAEA Reports

Update of control system for auxiliary pumping and primary water cooling facilities in JT-60 NBI

Kikuchi, Katsumi; Akino, Noboru; Ebisawa, Noboru; Ikeda, Yoshitaka; Seki, Norikazu*; Takenouchi, Tadashi; Tanai, Yutaka

JAEA-Technology 2008-034, 25 Pages, 2008/04

JAEA-Technology-2008-034.pdf:3.7MB

The control system for auxiliary pumping facility and primary water cooling facility in JT-60 NBI was updated. To realize the cost reduction, the control system with many input and outputs of 2000 was updated by JAEA itself using commercial Programmable Logic Controllers (PLC's). JAEA also made software with 3600 ladder lines by JAEA itself based on commercial basic programs. In addition to the simple replacement of the hardware and software, the function of remote operation has been newly added. At present, the auxiliary pumping facility and the primary water cooling facility have been stably operated without troubles. The remote operation enables to collect the detailed information on the trouble more easily, resulting in a quick countermeasure for the trouble.

Journal Articles

Long pulse production of high current D$$^{-}$$ ion beams in the JT-60 negative ion source

Hanada, Masaya; Kamada, Masaki; Akino, Noboru; Ebisawa, Noboru; Honda, Atsushi; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; Komata, Masao; Mogaki, Kazuhiko; et al.

Review of Scientific Instruments, 79(2), p.02A519_1 - 02A519_4, 2008/02

 Times Cited Count:6 Percentile:32.39(Instruments & Instrumentation)

A long pulse production of high-current, high-energy D$$^{-}$$ ion beams was studied in the JT-60U negative ion source that was designed to produce 22 A, 500 keV D$$^{-}$$ ion beams. Prior to the long pulse production, the short pulse beams were produced to examine operational ranges for a stable voltage holding capability and an allowable grid power loading. From a correlation between the voltage holding capability and a light intensity of cathodoluminescence from the insulator made of Fiber Reinforced Plastic insulator, the voltage holding was found to be stable at $$<$$ 340 kV where the light was sufficiently suppressed. The grid power loading for the long pulse operation was also decreased to the allowable level of $$<$$ 1 MW without a significant reduction of the beam power by tuning the extraction voltage (Vext) and the arc power (Parc). These allow the production of 30 A D$$^{-}$$ ion beams at 340 keV from two ion sources at Vacc = 340 kV. The pulse length was extended step by step, and finally reached up to 21 s, where the beam pulse length was limited by the surface temperature of the beam scraper without water cooling. The D$$^{-}$$ ion beams were neutralized to via a gas cell, resulting in a long pulse injection of 3.2 MW D$$^{0}$$ beams for 21 s. This is the first long injection of $$>$$ 20 s in a power range of $$>$$ 3 MW.

Journal Articles

Technical design of NBI system for JT-60SA

Ikeda, Yoshitaka; Akino, Noboru; Ebisawa, Noboru; Hanada, Masaya; Inoue, Takashi; Honda, Atsushi; Kamada, Masaki; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; et al.

Fusion Engineering and Design, 82(5-14), p.791 - 797, 2007/10

 Times Cited Count:20 Percentile:79.69(Nuclear Science & Technology)

Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject 34 MW for 100 s. The upgraded NBI system consists of twelve positive ion based NBI (P-NBI) units and one negative ion based NBI (N-NBI) unit. The injection power of the P-NBI units are 2 MW each at 85 keV, and the N-NBI unit will be 10 MW at 500 keV, respectively. On JT-60U, the long pulse operation of 30 s at 2 MW (85 keV) and 20 s at 3.2 MW (320 keV) have been achieved on P-NBI and N-NBI units, respectively. Since the temperature increase of the cooling water in both ion sources is saturated within 20 s, further pulse extension up to 100 s is expected to mainly modify the power supply systems in addition to modification of the N-NBI ion source for high acceleration voltage. The detailed technical design of the NBI system for JT-60SA is presented.

Journal Articles

Present status of the negative ion based NBI system for long pulse operation on JT-60U

Ikeda, Yoshitaka; Umeda, Naotaka; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hanada, Masaya; Honda, Atsushi; Inoue, Takashi; Kawai, Mikito; Kazawa, Minoru; et al.

Nuclear Fusion, 46(6), p.S211 - S219, 2006/06

 Times Cited Count:58 Percentile:87.29(Physics, Fluids & Plasmas)

Recently, the extension of the pulse duration up to 30 sec has been intended to study quasi-steady state plasma on JT-60U N-NBI system. The most serious issue is to reduce the heat load on the grids for long pulse operation. Two modifications have been proposed to reduce the heat load. One is to suppress the beam spread which may be caused by beamlet-beamlet interaction in the multi-aperture grid due to the space charge force. Thin plates were attached on the extraction grid to modify the local electric field. The plate thickness was optimized to steer the beamlet deflection. The other is to reduce the stripping loss, where the electron of the negative ion beam is stripped and accelerated in the ion source and then collides with the grids. The ion source was modified to reduce the pressure in the accelerator column to suppress the beam-ion stripping loss. Up to now, long pulse injection of 17 sec for 1.6 MW and 25 sec for $$sim$$1 MW has been obtained by one ion source with these modifications.

JAEA Reports

User's manual of a computer code for evaluating effectiveness of seismic component base isolation, EBISA; Function of dynamic response analysis code

Tsutsumi, Hideaki*; Sugino, Hideharu*; Onizawa, Kunio; Mori, Kazunari*; Yamada, Hiroyuki*; Shibata, Katsuyuki; Ebisawa, Katsumi*

JAEA-Data/Code 2006-004, 167 Pages, 2006/03

JAEA-Data-Code-2006-004.pdf:6.41MB

EBISA (Equipment Base Isolation System Analysis) code evaluates the effectiveness of seismic isolation for the important components in the seismic safety, and consists of the three codes, probabilistic seismic hazard code (SHEAT), seismic dynamic response analysis code (RESP) and seismic failure probability and frequency evaluation code. In these codes, RESP code is used for the calculation of the dynamic response behavior of a nuclear component with seismic isolation devices. This report describes the overall explanation of EBISA, and user's guide of RESP code including the analysis function, input manual and sample problem.

Journal Articles

Design and evaluation methodology for seismic base isolation of nuclear components by probabilistic approach

Tsutsumi, Hideaki*; Ebisawa, Katsumi*; Yamada, Hiroyuki*; Shibata, Katsuyuki; Fujimoto, Shigeru*

Nihon Zairyo Gakkai JCOSSAR 2003 Rombunshu, p.829 - 836, 2003/11

no abstracts in English

Journal Articles

Progress of negative ion source improvement in N-NBI for JT-60U

Kawai, Mikito; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hanada, Masaya; Honda, Atsushi; Inoue, Takashi; Kazawa, Minoru; Kikuchi, Katsumi*; Kuriyama, Masaaki; et al.

Fusion Science and Technology, 44(2), p.508 - 512, 2003/09

 Times Cited Count:4 Percentile:36.82(Nuclear Science & Technology)

The negative ion source for negative ion based neutral beam injector(N-NBI) of JT-60U aims at generating a negative ion beam with 500 keV and 22A for 10s. The N-NBI system was completed in 1996, followed by starting the efforts to increase beam power and energy. (1)Spatial non-uniformity of the source plasma causes position-dependent divergence of a beamlet due to mis-matching of local beam perveance. A part of the divergent energetic beams is intercepted by the grids and resultantly produce the excessive heat load of the grids and/or induce the high voltage breakdown. So several techniques to take measures against and to correct the non-uniformity in these sources were implemented. (2)Correction of beamlet deflection by adjusting the electric field at the extraction grids. It improved the beam divergence and then decreased an excessive heat load of a beam limiter by more than 50 %. As a result, the maximum injection power 6.2MW and beam pulse duration 10 seconds were obtaind.

Journal Articles

R&D of seismic emergency information transmission system

Ebisawa, Katsumi; Kuno, Tetsuya; Shibata, Katsuyuki; Oi, Masahiro*; Horiuchi, Shigeki*; Abe, Ichiro*; Tsuzuki, Kazuhisa*

Nihon Genshiryoku Gakkai Wabun Rombunshi, 1(2), p.177 - 190, 2002/06

no abstracts in English

JAEA Reports

SHEAT for PC: A Computer code for probabilistic seismic hazard analysis for personal computer, user's manual

Yamada, Hiroyuki; Tsutsumi, Hideaki*; Ebisawa, Katsumi*; Suzuki, Masahide

JAERI-Data/Code 2002-001, 161 Pages, 2002/03

JAERI-Data-Code-2002-001.pdf:6.62MB

no abstracts in English

JAEA Reports

Study on the dynamic response analysis for evaluating the effectiveness of base isolation for nuclear components

Mori, Kazunari*; Tsutsumi, Hideaki*; Yamada, Hiroyuki; Ebisawa, Katsumi; Shibata, Katsuyuki

JAERI-Tech 2001-037, 85 Pages, 2001/06

JAERI-Tech-2001-037.pdf:6.27MB

no abstracts in English

JAEA Reports

Shaking table test and dynamic response analysis of 3-D component base isolation system using multi-layer rubber bearings and coil springs

Tsutsumi, Hideaki*; Yamada, Hiroyuki; Ebisawa, Katsumi; Shibata, Katsuyuki; Fujimoto, Shigeru*

JAERI-Tech 2001-033, 124 Pages, 2001/06

JAERI-Tech-2001-033.pdf:9.98MB

no abstracts in English

JAEA Reports

Earthquake observation database in JAERI Oarai site obtained by vertical instrument arrays from 1987-2000

Ebisawa, Katsumi; Yamada, Hiroyuki; Tsutsumi, Hideaki*; Shibata, Katsuyuki; Ando, Kazuhiro*; Baba, Osamu; Suzuki, Hideyuki

JAERI-Data/Code 2001-009, 96 Pages, 2001/03

JAERI-Data-Code-2001-009.pdf:4.14MB

no abstracts in English

JAEA Reports

Characteristics and dynamic response analysis of 3-D component base isolation system using ball bearings and air springs

Tsutsumi, Hideaki*; Yamada, Hiroyuki; Mori, Kazunari*; Ebisawa, Katsumi; Shibata, Katsuyuki

JAERI-Tech 2000-086, 93 Pages, 2001/02

JAERI-Tech-2000-086.pdf:6.56MB

no abstracts in English

41 (Records 1-20 displayed on this page)