Probabilistic risk assessment method development for high temperature gas-cooled reactors, 1; Project overviews

Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Muramatsu, Ken*; Muta, Hitoshi*; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; Yamamoto, Tsuyoshi*; et al.

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04

JAEA, in conjunction with Tokyo City University, The University of Tokyo and JGC Corporation, have started development of a PRA method considering the safety and design features of HTGR. The primary objective of the project is to develop a seismic PRA method which enables to provide a reasonably complete identification of accident scenario including a loss of safety function in passive system, structure and components. In addition, we aim to develop a basis for guidance to implement the PRA. This paper provides the overview of the activities including development of a system analysis method for multiple failures, a component failure data using the operation and maintenance experience in the HTTR, seismic fragility evaluation method, and mechanistic source term evaluation method considering failures in core graphite components and reactor building.

The Activities for improvement of hot environment in undergrounding pipe-space(trench), 1; The Decrease of the radiant heat from steam pipe

Ishiyama, Toru; Kawasaki, Ichio; Matsumoto, Takenari; Terada, Hideyuki; Kikuchi, Akio; Mizoguchi, Tsuyoshi*; Ikede, Hiroyuki*

Nihon Hozen Gakkai Dai-8-Kai Gakujutsu Koenkai Yoshishu, p.82 - 87, 2011/10

In the undergrounding pipe-space, there are many pipes for utility (electronic cable, water, gas, steam, etc.). These pipes are kept to safe by daily inspection. But hot environment of the pipe-space affects badly the device and a laborer's health. The investigation of the heat distribution was carried on, therefore it was found that the radiant heat around the valve was very much. The method of thermal insulation was examined from the view point of the shape, cost, and effect. Then some of valves were covered with flexible thermal insulation, and the temperature of the area around the covered valves was decreased about 10C.

Development of high-level application framework with a script language JCE for accelerator beam commissioning

Sako, Hiroyuki; Ikeda, Hiroshi*

Proceedings of 12th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2009) (CD-ROM), p.848 - 850, 2009/10

A high-level application framework based on script language, J-PARC Commissioning Environment (JCE), has been developed in Java. It is capable of device control via EPICS, a beam transport simulation, GUI components, mathematical functions, which are flexibly and seamlessly combined in the script. Modularity, code understandability, and extensibility are achieved. JCE has been utilized successfully for beam commissioning of J-PARC linac.

Development of a plasma generator for a high power NBI ion source

Dairaku, Masayuki; Watanabe, Kazuhiro; Tobari, Hiroyuki; Kashiwagi, Mieko; Inoue, Takashi; Sakamoto, Keishi; Hanada, Masaya; Akino, Noboru; Ikeda, Yoshitaka; Yamamoto, Takumi*

JAEA-Technology 2008-091, 23 Pages, 2009/03

JAEA-Technology-2008-091.pdf:5.82MB

A plasma generator whose inner dimensions are 25 cm in width, 59 cm in length, and 31 cm in depth for a high power and long pulse ion source in neutral beam injector has been designed and fabricated. The plasma generator has a beam extraction area of 12 cm in width and 46 cm in length. A target of the output beam using the plasma generator is to produce deuterium positive ion beams up to 120 keV, 65 A for longer than 200 s pulses. Arrangement of the permanent magnets and filaments has been designed by using an electron trajectory simulation code to produce uniform and high density plasma with high proton yield. Cooling channels have been also designed to operate the long pulse plasma generation with a 100 kW arc discharge power.

Performance of the control system for the J-PARC LINAC

Yoshikawa, Hiroshi; Suzuki, Takahiro; Sakaki, Hironao; Ito, Yuichi; Kato, Yuko; Kawase, Masato; Sako, Hiroyuki; Shen, G.; Takahashi, Hiroki; Fukuta, Shimpei; et al.

Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.52 - 54, 2009/00

http://accelconf.web.cern.ch/accelconf/LINAC08/papers/mop003.pdf

LINAC of J-PARC began to operate in November, 2006, and a achieved an initial performance in January, 2007. Afterwards, the beam supply to RCS begins, and it is operating extremely with stability up to now. Here, the evaluation for comparison of the design and realities of architecture and performance of the LINAC control system are shown. Especially, the conceptual idea of function arrangement in the hierarchy of the control system architecture is shown. Now, the LINAC control system is in the second phase for the high power beam and reducing the beam loss, and the analysis of the system response identification for the high precision beam control is started.

P-NMR study of the neptunium-based filled-skutterudite NpFeP

Tokunaga, Yo; Aoki, Dai*; Homma, Yoshiya*; Sakai, Hironori; Chudo, Hiroyuki; Kambe, Shinsaku; Matsuda, Tatsuma; Ikeda, Shugo; Yamamoto, Etsuji; Nakamura, Akio; et al.

Journal of the Physical Society of Japan, 77(Suppl.A), p.211 - 213, 2008/00

https://doi.org/10.1143/JPSJS.77SA.211

P-NMR measurements have been performed on a single crystal of NpFeP which is the first crystallized transuranium filled-skutterudite compound. The field-orientation dependence of the hyperfine interaction has been measured using the single crystal, and the results compared with those obtained previously in isostructural compounds UFeP and PrFeP. We have also measured the field and temperature dependence of the nuclear spin-lattice relaxation rate in several fields between 1.8 and 8 T at temperatures between 4.2 and 300 K. The results are discussed on the basis of a localized picture for the 5f electrons.

Current status of the control system for J-PARC accelerator complex

Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.

Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10

J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.

R&D progress at JAEA towards production of high power and large-area negative ion beams for ITER

Hanada, Masaya; Inoue, Takashi; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Watanabe, Kazuhiro; Umeda, Naotaka; Dairaku, Masayuki; Ikeda, Yoshitaka; Sakamoto, Keishi

Nuclear Fusion, 47(9), p.1142 - 1146, 2007/09

https://doi.org/10.1088/0029-5515/47/9/010

The paper reports the progress of R&D toward the ITER neutral beam (NB) system at Japan Atomic Energy Agency (JAEA). In the accelerator development, an H ion beam of 146 A/m was accelerated up to 836 keV in a vacuum insulated accelerator with five acceleration stages. This is the first production of a high power density beam at MeV range energy, which is more than twice higher than those of the existing NB systems for large experimental reactors such as JT-60U. Long pulse operations of the JT-60U negative ion sources with a large extraction area of 0.45 1.1 m are in progress. From two ion sources, D ion beams of 21 A (90 A/m), 320 keV have been produced for 21 s. As the consequence, injection of 3.2 MW D0 beams was achieved. Thus the long pulse operation of negative ion based NB system has been demonstrated with multi-tens of ampere of D ions extracted from the ion extraction area relevant to the ITER NB design (0.6 1.5 m). For long pulse operation of such powerful beams, the negative ion uniformity over the wide extraction area is an essential issue to avoid excess power loading on the accelerator grids. By adopting a new magnetic configuration with so called tent shaped filter, the uniformity of the JAEA 10 ampere source (extraction area: 0.13 0.22 m) was improved to be 8%, which fulfilled the ITER requirement.

Construction of GUI for J-PARC LINAC machine protection system

Ishiyama, Tatsuya*; Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Ito, Yuichi; Kato, Yuko; Kawase, Masato; Ueda, Shinji*; Sugimoto, Makoto*; et al.

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.370 - 372, 2006/00

no abstracts in English

Al NMR study of Np-based superconductor NpPdAl, 4

Chudo, Hiroyuki; Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Aoki, Dai*; Homma, Yoshiya*; Shiokawa, Yoshinobu*; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo*; et al.

no journal, , 

no abstracts in English