Koga, Kazuhiro*; Suzuki, Kazunori*; Takagi, Tsuyohiko; Hamano, Tomoharu
FAPIG, (196), p.8 - 15, 2020/01
The prototype fast breeder reactor Monju has already started (from June 2017) the unloading operation period (about 5.5 years: until the end of 2022) of the fuel assembly, which is the first stage of decommission. Among them, the first "Processing of fuel assembly" operation (86 in total) was conducted from August 2018 to January 2019 as the first handling of the fuel assembly. Fuji Electric provided technical support, such as dispatching technicians throughout the period, in cooperation with Japan Atomic Energy Agency for the "Processing of fuel assembly" operation, and contributed to the completion of the operation while experiencing various troubles. This manuscript introduces the contents of the first "Processing of fuel assembly" operation and the overview of the trouble status. This manuscript is a sequel to FAPIG No.194 "Prototype Fast Breeder Reactor Monju Decommissioning and Unloading Operation of the Fuel Assembly from the Core", please refer to it.
Koga, Kazuhiro*; Suzuki, Kazunori*; Hamano, Tomoharu; Takagi, Tsuyohiko
FAPIG, (194), p.6 - 11, 2018/02
The prototype fast breeder reactor "Monju" was decided to decommission by Japanese government on 21 December 2016. After that, Japan Atomic Energy Agency (JAEA) submitted "Monju decommissioning basic plan" to MEXT (Charge ministry) on 13 June 2017, then the unloading operation period (about 5.5 years) of the fuel assembly, which is the first stage of decommission, has started. Fuji Electric is proceeding with various preparations in cooperation with JAEA for the safe work of the unloading operation. This manuscript introduces the outline of preparation situation such as maintenance and inspection for the unloading operation.
Uchiyama, Naoki*; Ozawa, Tatsuya*; Sato, Koji*; Kobayashi, Jun; Onojima, Takamitsu; Tanaka, Masaaki
FAPIG, (194), p.12 - 18, 2018/02
no abstracts in English
Koga, Kazuhiro*; Ohara, Norikazu*; Ino, Hiroichi*; Kondo, Katsumi*; Ito, Hideaki; Ashida, Takashi; Nakamura, Toshiyuki
FAPIG, (190), p.3 - 8, 2015/07
no abstracts in English
Tsuji, Nobumasa*; Ohashi, Kazutaka*; Tazawa, Yujiro*; Tachibana, Yukio; Ohashi, Hirofumi; Takamatsu, Kuniyoshi
FAPIG, (190), p.20 - 24, 2015/07
In a loss of forced cooling accident, decay heat in HTGRs must be removed by radiation, thermal conduction and natural convection. Passive heat removal performance is of primary concern for enhancing inherent safety features of HTGRs. Therefore, the thermal hydraulic analyses for normal operation and a loss of forced cooling accident are conducted by using thermal hydraulic CFD code. And further, a multi-hole type fuel block of MHTGR is also modeled and the flow and heat transfer characteristics are compared with a pin-in-block type fuel block.
Yamada, Hirokazu*; Sakurai, Shinji; Nakamura, Shigetoshi
FAPIG, (187), p.28 - 31, 2014/02
The activity of "Broader approach (BA)" is carried out under the Japan-EU collaboration towards the early realization of nuclear fusion energy, and the construction of JT-60SA (Super Advanced) has been started as a part of BA. Divertor target of JT-60 consisted of carbon fiber composite tiles bolted on heat sink plate. Due to extension of plasma heating power and pulse duration, divertor target for JT-60SA has to be changed to the concept of carbon fiber block jointed to cooling tube of Cu-alloy for active cooling. Brazing joint between the carbon block and cooling tube is easy to cause joint defect due to the difference in the coefficient of linear expansion of a material. The joint defect reduces heat removal performance of the target. On the occasion of the apparatus manufacture concerned, the structural improvement realized those problems. This paper reports the contents of a structural improvement in the divertor target manufacturing for JT-60SA, etc.
Chida, Yutaka; Nakajima, Hideo
FAPIG, (182), p.15 - 20, 2011/02
no abstracts in English
Shimizu, Futoshi; Sakamoto, Kensaku; Yoshioka, Yuji*
FAPIG, (182), p.26 - 29, 2011/02
no abstracts in English
Suzuki, Yoshihiro*; Arai, Yasushi*
FAPIG, (182), p.9 - 14, 2011/02
Plan of plutonium use in nuclear reactors to make good use of uranium resource is making progress in Japan for FBR and LWR. Among these reactors, for FBR Monju, MOX fuel has been produced in JAEA MOX fuel plant from 1988. And the start of MOX fuel production in JNFL plant for LWR was decided and the plant construction started in 2010. Fuji Electric has designed and manufactured the production equipment of MOX fuel for FBR from 1990s. As a recent result Fuji Electric supplied equipment(2) of MOX pellet finishing and inspection to JAEA in February 2010. In this document we introduce the summary of equipment(2) of MOX pellet finishing and inspection.
Ise, Hideo; Ogiyanagi, Jin; Nakamura, Jinichi; Sasajima, Hideo; Takasa, Akira; Hanawa, Satoshi; Kawaguchi, Yoshihiko; Chimi, Yasuhiro; Nishiyama, Yutaka; Nakamura, Takehiko
FAPIG, (180), p.22 - 25, 2010/02
Refurbishment of Japan Materials Testing Reactor (JMTR) is conducted in Japan Atomic Energy Agency (JAEA) in order to solve irradiation related issues for safe long-term operation of current light water reactors (LWRs) and development of advanced LWRs. JMTR will restart its operation in FY 2011. Manufacturing and installation of the irradiation test facilities on safety research of fuels and materials are also in progress. The outline of the fuels and materials irradiation test plan is described in this report.
Terauchi, Makoto; Masai, Jo; Suzuki, Shintaro*
FAPIG, (180), p.30 - 35, 2010/02
Prototype fast breeder reactor in Japan Atomic Energy Agency "MONJU", the aim of strengthening the safety and reliability of maintenance management, maintenance management system from client-server system of updating the Websystem. Fiscal 2008 the Web system started a new maintenance management systems approach. In this paper, we introduce the features and functions of the new maintenance management system.
Saito, Takakazu; Imaizumi, Kazuyuki; Oka, Kiyoshi; Aizawa, Hideyuki*; Katagiri, Genichi*
FAPIG, (179), p.3 - 9, 2009/07
The experimental fast reactor Joyo is the first sodium cooled fast reactor in Japan. In-vessel visual inspections have been conducted with an obstacle on the in-vessel storage rack in Joyo. Because of the high radiation dose in the reactor vessel, radiation-resistant fiberscope was applied to Joyo. The radiation-resistant fiberscope was inserted into the reactor vessel thorough the inspection hole and fuel handling hole on rotating plugs. In order to observe the top of the subassemblies and in-vessel storage rack, an I-shape device which had a downward and side view monitoring radiation-resistant fiberscopes was used. To observe the bottom face of the upper core structure, a remote handling visual device whose tip could bend into an L-shape was developed to insert the radiation-resistant fiberscope into the 70 mm gap between the bottom of the upper core structure and the top of the subassemblies. The observations of the top of the subassemblies and in-vessel storage rack were conducted from October 2007 to February 2008. The bottom face of the upper core structure was observed in July 2008. The number of photographs of the entire bottom face of the upper core structure reached approximately 35,000. Confirmation was made that the remote handling device equipped with the radiation-resistant fiberscope would achieve the expected performance. These observations results provided useful information on incident investigations. In addition, fundamental findings and the experience gained during this study, which included the design of equipment, operating procedures, resolution, lighting adjustments, photograph composition and the durability of the radiation-resistant fiberscope under radiation exposure, provided valuable insights into possible further improvements and verifications for in-vessel visual observation techniques in an sodium fast reactor.
Iimura, Koichi; Sakamoto, Taichi; Kanno, Masaru; Hori, Naohiko
FAPIG, (178), p.14 - 18, 2009/02
At Oarai Research and Development Center, Japan Atomic Energy Agency (JAEA) advances the plan of refurbishing Japan Materials Testing Reactor (JMTR) to start the operation in fiscal 2011. As part of effective use for JMTR, JAEA is planning to product Mo, which is a parent nuclide of Tc. Tc is most commonly used as a radiopharmaceutical in the field of nuclear medicine. Currently the supplying of Mo is only depend on imports from foreign countries, so JAEA is aiming at domestic production of a part of Mo in cooperation with the industrial circles. In this article, JAEA introduced the Conceptual Plan about the choice and fabric of the irradiation facilities for Mo production, and commercializing equipment after irradiation for Mo production.
Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Hanano, Kohei; Futakawa, Masatoshi
FAPIG, (177), p.12 - 17, 2008/07
The construction of the mercury target system which is the 1MW class spallation neutron source under the J-PARC project has been completed. The mercury target system consists of the mercury target vessel, the mercury circulation system and the target trolley. The outline of the spallation neutron source in the material and life science experimental facility, and the mercury target system is reported. Several topics appeared in the course of the system fabrication and assembling are also reported. For the target vessel, the residual stress at the beam window was evaluated, and it was confirmed that the stress level is low and no problem. For the mercury pump, the outer shape and the structure of the mechanical PM pump which was newly developed and its operational results are reported. For the target trolley, the characteristic structure where all of the mercury related devices are mounted on the single trolley is reported.
Hashimoto, Daisuke*; Komatsu, Keiichi*; Eguchi, Kenji*; Morizono, Koji
FAPIG, (175), p.23 - 28, 2007/07
The fast breeder reactor "MONJU" (hereafter "MONJU") is equipped with the system called "MONJU Integrated Data Acquisition System (MIDAS)" to effectively acquire, accumulate and analyze relevant real-plant process data gathered from the system start-up test. At present, "MONJU" has been suspended due to a sodium leak accident that occurred in 1995. However, the main part of remodeling construction to prevent sodium leaks was completed in May, 2007 and "MONJU" is highly expected to resume its operations, stepping into the practical testing phase. In this situation, "MIDAS" has been replaced with an upgraded version before the system start-up test was resumed. This paper describes overview of the new "MIDAS" system.
FAPIG, (175), p.3 - 17, 2007/07
According to the established agreement on construction of International Thermonuclear Experimental Reactor ITER in France, many engineers of the participant countries of ITER project have left for their new assignments to the Cadarache work site since the middle of 2006. This paper reports an overseas life, which has been experienced by the author for the first time, over a long period of time from last November with focus on personal experience and impression. With introduction of the work site of CEA research center of Cadarache, residence place Aix-en-Provence and the region of Provence including them, there are described environments and troubles in dairy life, a wall of foreign language, and pleasures of weekends.
FAPIG, (174), p.5 - 10, 2007/02
The operation of Proto-type Fast Breeder Reactor MONJU has been suspended since December 1995, due to the sodium leak accident at the secondary cooling system. The construction work for sodium leak event is progressing from September 2005, to solve the problems pointed out in the general safety investigation of MONJU carried out after this accident. 90% of the construction work was completed at the end of December 2006. The confirmation test was already started from December 18, 2006. This report describes the present status of MONJU, mainly about the progress and results of the construction work performed by Fuji Electric Systems co., Ltd. and Kawasaki Plant Systems, Ltd.
Minami, Takahiro; Suzuki, Yoshio; Aoyagi, Tetsuo; Ito, Toshinori*; Nakajima, Norihiro
FAPIG, (174), p.31 - 39, 2007/02
The Center for Computational Science and E-systems of the Japan Atomic Energy Agency (CCSE/JAEA) has started a program to construct an international computational infrastructure in atomic energy research field called the AEGIS (Atomic Energy Grid InfraStructure) in April, 2006. The development is based on numerous experiences and technologies acquired from the development of the STA (Seamless Thinking Aid) and the ITBL (Information Technology Based Laboratory) infrastructure software. In this paper, we will introduce two key achievements prior to the AEGIS program: "Interoperable system between UNICORE in Germany and ITBL" which achieves international sharing of computational resources, and the "STARPC Plus" which can construct a compact grid system.
Yamada, Hirokazu*; Tsuchiya, Kunihiko
FAPIG, (173), p.16 - 20, 2006/07
no abstracts in English
Takehara, Kazuki*; Sasa, Yoichi; Sekita, Tsutomu
FAPIG, (173), p.21 - 29, 2006/07
no abstracts in English