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Suwa, Masayuki; Fukushima, Manabu; Terunuma, Noriaki; Ota, Kazunori; Murayama, Yoji
no journal, ,
no abstracts in English
heating field in JMTRImaizumi, Tomomi; Takemoto, Noriyuki; Nagao, Yoshiharu
no journal, ,
The renewed and upgraded JMTR will start from FY 2011. The JMTR will be use to irradiation test about lifetime extension of light water reactors (LWRs), progress of science and technology, and expansion of industry use. To lifetime extension of LWRs, it is demanded the irradiation test to confirm integrity of reactor structural materials such as stainless steel and concrete, etc. In irradiation tests of concrete sample, it is necessary to keep low irradiation temperature to prevent dehydration of cement hydrates or thermal stress. However, irradiation samples are heated by rays. On the other hand, neutron irradiation test in low heating field is effective as progress of science and technology such as materials basic research. Therefore, the neutron irradiation field of low heating rate was designed in JMTR. In this study, it was considered that the heating rate is below 0.07 W/g in the JMTR core so as not to become higher temperature as planned.
Takemoto, Noriyuki; Kitagishi, Shigeru; Tsuchiya, Kunihiko; Nagao, Yoshiharu; Ishihara, Masahiro; Kawamura, Hiroshi
no journal, ,
The JMTR is being refurbished and the upgraded reactor will restart from FY 2011. To conduct attractive irradiation tests after refurbished, the new reflector element which has a housing structure with beryllium or aluminum pebbles packing was developed to advance the neutron irradiation control. As results of neutronic calculation, it was found that continuously variable control of thermal neutron flux or neutron spectrum is possible within control capability limits between the beryllium reflector element and the aluminum one by changing of packing fraction of pebbles. As a result of investigation about specification of beryllium pebbles, filling method, housing structure and so on, it was confirmed that the new reflector element is possible to fabricate. Therefore, it would be possible to fine-grained control of neutron irradiation condition by applying the new reflector element.
Onuma, Yuichi; Okada, Yuji; Hanawa, Hiroshi; Tsuchiya, Kunihiko; Kanno, Masaru
no journal, ,
The Japan Materials Testing Reactor (JMTR) has been refurbished for re-operation of 2011. As a part of the establishment of new irradiation facilities, technology development has been performed for the dismantling and removing of irradiation facilities such as OWL-1 (Oarai Water Loop No.1), OWL-2 (Oarai Water Loop No.2) and IASCC (Irradiation Assisted Stress Corrosion Cracking) facility installed in the JMTR cubicles. In this report, the study for dismantling and removing of irradiation facilities.
Kitagishi, Shigeru; Iimura, Koichi; Inoue, Shuichi; Saito, Takashi; Omi, Masao; Tsuchiya, Kunihiko
no journal, ,
no abstracts in English
Dorn, C. K.*; Tsuchiya, Kunihiko; Hatano, Yuji*; Chakrov, P.*; Kodama, Mitsuhiro*; Kawamura, Hiroshi
no journal, ,
no abstracts in English
Tc extraction techniques from 
Mo by (n,) reactionKimura, Akihiro; Hori, Naohiko; Tsuchiya, Kunihiko; Ishihara, Masahiro; Yamabayashi, Hisamichi*; Tanase, Masakazu*; Fujisaki, Saburo*; Sato, Yuichi*
no journal, ,
Production techniques of Mo, parent nuclide of Tc, have been developed for the industrial utilization as medical diagnosis medicine after the JMTR refurbishment. The (n,) method is proposed in JMTR because of low-amount radioactive wastes and easy Tc production process. In this study, the production of the high-density MoO
pellet and concentration techniques of Tc solution were developed. As the trial test, the MoO pellets with high density were produced by the SPS (Spark Plasma Sintering) method. On the other hands, it was possible to concentrate Tc solution by the solvent extraction using Methyl Ethyl Ketone (MEK). From the result, the Tc concentrating device with more than 80% concentration efficiency, was performed successfully.
Nemoto, Hiroyoshi; Ebisawa, Hiroyuki; Takahashi, Masayoshi*; Ihara, Yoshihisa*; Ogasawara, Yasushi; Echigoya, Shinichi
no journal, ,
JMTR (Japan Materials Testing Reactor) has started refurbishment of reactor facilities from FY2007, and the renewed and upgraded JMTR will start from FY2011. Control system of the JMTR has been used for 42 years since first criticality in 1968. Distributed control system (DCS) introduced in this project will enable the operators to monitor and control the entire plant information on a unified platform and realize digitalization / integration of various data. In addition, adoption of large screens will make it possible to show versatile information collectively, and it will lead to increase operability, visibility and assistance for plant operators. For the reactor control room, new layout design is introduced based on desired ergonomics. This report summarizes the outline of refurbishment project on plant control upgrading from analog control panels to the latest distributed control system (DCS).
Ishihara, Masahiro; Kusunoki, Tsuyoshi; Niimi, Motoji; Kawamura, Hiroshi
no journal, ,
The JMTR has been applied to fuel/material irradiation examinations for LWRs, HTGR, fusion reactor and RI production. However, the JMTR operation was stopped in August 2006, and now its refurbishment is conducting. The reactor facilities will be renewed during four years from the beginning of FY 2007, and necessary examination and works are carrying out on schedule. The renewed JMTR will be started from FY 2011, and be operated for a period of about 20 years. In this presentation, status of the refurbishment of reactor facilities are introduced, moreover the future program using the JMTR will be explained.
Onoue, Ryuji; Ebisawa, Hiroyuki; Fukasaku, Akitomi; Kusunoki, Tsuyoshi
no journal, ,
no abstracts in English
Oto, Tsutomu; Kimura, Tadashi; Fukasaku, Akitomi; Kusunoki, Tsuyoshi
no journal, ,
The refurbishment of JMTR is scheduled from the beginning of FY 2007 to the end of FY 2010. An integrity investigation for concrete structures of the JMTR buildings was carried out in early phase of the refurbishment. These concrete structures have been used for more than 40 years after completion of the construction and are expected to be used more than 20 year from restart of the JMTR. The investigated items were the concrete surface deterioration, the rebound number (nondestructive strength test), the comprehensive strength using drilled concrete core test piece, the carbonation depth, the reinforced bar corrosion and the chloride ion content. This paper describes the investigated results and repair work of the vent stack, the trenches, the canal building and the filter bank.
Yonekawa, Minoru; Sozawa, Shizuo; Kato, Yoshiaki; Nakagawa, Tetsuya; Kusunoki, Tsuyoshi
no journal, ,
The hot laboratory (JMTR-HL) was founded to examine the objects mainly irradiated in the JMTR, and has been operated since 1971. The JMTR has been stopped from FY2006 for the refurbishment and will be re-started from FY2011. The post irradiation examination for high burn up fuels and large specimen will be carried out in the restarted JMTR. The JMTR-HL plans to put a three dimensional X-ray radiography system in place until the restart of JMTR in order to satisfy the requirement of valuable irradiation data for safety and plant life time management of nuclear power plants in the future. The three dimensional X-ray radiography system is able to observe a defect geometry closely and visually compared with a two dimensional system. The performance check using a simulated fuel showed an acceptable result. The three dimensional X-ray radiography system will be used for the post irradiation examination for high burn up fuels and large specimen after the JMTR re-start.