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Ide, Hiroshi; Sakuta, Yoshiyuki; Hanawa, Yoshio; Tsuji, Tomoyuki; Tsuboi, Kazuaki; Nagao, Yoshiharu; Miyazawa, Masataka
JAEA-Technology 2009-019, 28 Pages, 2009/06
The main body of the JMTR is composed of reactor pressure vessel, core and reactor pool. At the bottom of the reactor pool, the Diaphragm-seal (2.6m outer diameter, 2m inner diameter, thickness 1.5mm) of the JMTR made of stainless steel is installed to prevent the water leak of the reactor pool and to absorb the expansion of the reactor pressure vessel due to pressure and temperature changes. Prior to the refurbishment of the JMTR, the inspection device which is a deposition-collection apparatus with underwater-camera was developed, and the visual inspection was carried out to confirm the soundness of the diaphragm-seal. As a result, harmful flaws and/or corrosions were not inspected in the visual inspection, and the soundness of the diaphragm seal was confirmed. In future, the long-term integrity of the diaphragm-seal will could be achieved by conducting the periodic inspection.
Ide, Hiroshi; Naka, Michihiro; Sakuta, Yoshiyuki; Hori, Naohiko; Matsui, Yoshinori; Miyazawa, Masataka
JAEA-Review 2008-076, 442 Pages, 2009/03
The safety design examination guides for water-cooled reactors for test and research was gathered in safe examination of the licensing as the purpose of showing the basics when the validity of the design is judged about from the viewpoint of keeping safety. For the confirmation of the JMTR reactor facility conforming the current guides, the check of the items mentioned in the licensing documents, annexes of licensing documents and related documents were carried out. As the result of check, there was the mention about conformity in licensing and so on. And the constructs, systems and devices which have safety functions have been produced under authorization of regulating authority. Therefore it was confirmed that the licensing were conformed to guides and the JMTR has enough performance.
Takemoto, Noriyuki; Hanawa, Yoshio; Gorai, Shigeru; Fukasaku, Akitomi; Miyazawa, Masataka; Niimi, Motoji
JAEA-Conf 2008-010, p.97 - 105, 2008/12
Operation of the Japan Materials Testing Reactor (JMTR), a light-water-cooling tank-type reactor with a 50 MW thermal power, was stopped in August 2006, and now its refurbishment is on going. The reactor facilities are to be refurbished during four years from the beginning of FY 2007, and the renewed JMTR will be operated from FY 2011 until around FY 2030. As for the decision of the refurbishment, reactor facilities to be renewed and to be continuously used were selected from a viewpoint of ensuring safety, improvement of availability-factor, etc. The selected renewal reactor facilities were the reactor instrument and control system, cooling system, radioactive waste facility, power supply system, boiler, etc. Presented are the basic idea on selection of the renewal facilities, outline of these facilities and schedule of refurbishment work.
Takemoto, Noriyuki; Izumo, Hironobu; Inoue, Shuichi; Abe, Shinichi; Naka, Michihiro; Akashi, Kazutomo; Omi, Masao; Miyazawa, Masataka; Baba, Osamu*; Nagao, Yoshiharu
JAEA-Review 2008-051, 36 Pages, 2008/10
The JMTR has been refurbished to restart operation in FY2011. The restarted JMTR plays roles of (1) measures for long-term operation of light water reactors, (2) improvement in scientific technique, (3) increase of industrial use, (4) training of human resources, etc. It is needed to operate the restarted JMTR safety and stably and maintain high available factor (5070%) because of increasing of irradiation utilization demand. In this report, measures for training of reactor operators, organization for operating, etc were proposed to operate reactor safety and smoothly. And also reactor operation procedure was examined to improve available factor up to world level for materials testing reactor. As a result, it was turned out to be possible to realize stably 210 days operation per year (available factor: 60%).
Sagawa, Hisashi; Koda, Nobuyuki; Hanawa, Nobuhiro; Maruo, Takeshi; Miyazawa, Masataka; Unesaki, Hironobu*; Nakagome, Yoshihiro*
IAEA-TECDOC-1593, p.121 - 128, 2008/06
In Japan, 1,712 of Research Reactor Spent Nuclear fuels (RRSNFs) have been transported to the US successfully since the receipt in accordance with the foreign research reactor spent nuclear fuel acceptance policy started in 1996. Especially, Japan Atomic Energy Agency (JAEA) carried out shipment to the US of eight times and of 1,283 fuel elements in total. This paper describes experiences of RRSNF transportation to the US in Japan.
Nagao, Yoshiharu; Miyazawa, Masataka; Komukai, Bunsaku; Fujiki, Kazuo
JAERI-Tech 2003-067, 33 Pages, 2003/07
no abstracts in English
; Miyazawa, Masataka; ; ; ; Yamamoto, Katsumune; Oyamada, Rokuro; Saito, Minoru
JAERI-M 93-227, 73 Pages, 1993/12
no abstracts in English
Miyazawa, Masataka; Itabashi, Yukio; ; ; ; ; ; Oyamada, Rokuro;
9th Int. Symp. on Packaging and Transportation of Radioactive Materials, Vol. 3, p.1686 - 1693, 1989/00
no abstracts in English
Hanakawa, Hiroki; Fukasaku, Akitomi; Nagao, Yoshiharu; Miyazawa, Masataka; Niimi, Motoji
no journal, ,
no abstracts in English
Hanakawa, Hiroki; Hanawa, Yoshio; Izumo, Hironobu; Fukasaku, Akitomi; Nagao, Yoshiharu; Miyazawa, Masataka; Niimi, Motoji
no journal, ,
The refurbished JMTR will start on FY 2011, and operate for a period of about 20 years. Before this plan, preliminary inspection of secondary cooling system piping was carried out in order to make a maintenance plan. As the results of this inspection, it was confirmed that the corrosion was reached by piping ingot, or decrease of piping thickness could hardly be observed. It was therefore confirmed that the strength or the functionality of the piping had been maintained by usual operation and maintenance. According to the results of this inspection, the basic date for maintenances are confirmed and it is clear to be able to make the maintenances plan in future.
Watahiki, Shunsuke; Nakamichi, Masaru; Naka, Michihiro; Saito, Takashi; Ide, Hiroshi; Miyazawa, Masataka; Ishihara, Masahiro; Kawamura, Hiroshi
no journal, ,
The development of in-core remote sensing Technology is essential to aim at the realizayion of advanced irradiation examination in the new JMTR. By observing the in-core on real time and taking out nucleus and thermal information as optical information, the technology may be able to detect a very small change of the in-core, which is undetectable by the usual instrumentation. As a result, a highly accurate irradiation examination can be done. In the present study(work), the spent fuel kept in the spent fuel rack in the canal(water way) of JMTR was recorded with a video camera(visible light), and the brightness of Cherenkov radiation was evaluated from the radiation the obtained image.
Kawamura, Hiroshi; Niimi, Motoji; Ishihara, Masahiro; Miyazawa, Masataka; Hori, Naohiko; Nagao, Yoshiharu
no journal, ,
The Japan Materials Testing Reactor (JMTR) of Japan Atomic Energy Agency (JAEA) is a light water cooling tank typed reactor with first criticality in March 1968. The JMTR has been applied to fuel/material irradiation examinations for LWRs, HTGR, fusion reactor and RI production. Owing to the connection between the JMTR and hot laboratory by a canal, easy re-irradiation tests can conduct with safety and quick transportation of irradiated samples. The JMTR operation was stopped in August 2006 in order to conduct its refurbishment. The reactor facilities will be refurbished during four years from the beginning of FY 2007, and necessary examination and work are carrying out on schedule. The renewed JMTR will be started from FY 2011, and be operated for a period of about 20 years (until around FY 2030). The usability improvement of the JMTR, e.g. higher reactor available factor, shortening turnaround time to get irradiation results, attractive irradiation cost, business confidence, is also discussing as the preparations for re-operation.
Hanakawa, Hiroki; Watahiki, Shunsuke; Echigoya, Shinichi; Miyazawa, Masataka
no journal, ,
no abstracts in English