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Onoue, Ryuji; Kawamata, Takanori; Otsuka, Kaoru; Sekine, Katsunori; Koike, Sumio; Gorai, Shigeru; Nishiyama, Yutaka; Fukasaku, Akitomi
JAEA-Review 2012-010, 116 Pages, 2012/03
JAEA-Review-2012-010-01.pdf:65.41MBJAEA-Review-2012-010-02.pdf:81.33MBJAEA-Review-2012-010-03.pdf:87.98MBJAEA-Review-2012-010-04.pdf:45.25MB
JMTR is a light water moderated and cooled tank-type reactor, and its thermal power is 50 MW. The JMTR is categorized as high flux testing reactors in the world. The JMTR has been utilized for irradiation experiments of nuclear fuels and materials, as well as for radioisotope productions since the first criticality in March 1968 until August 2006. JAEA is decided to refurbish the JMTR as an important fundamental infrastructure to promote the nuclear research and development. And The JMTR refurbishment work is carried out for 4 years from 2007. Before refurbishment work, from August 2006 to March 2007, all concerned renewal facilities were selected from evaluation on their damage and wear in terms of aging. Facilities which replacement parts are no longer manufactured or not likely to be manufactured continuously in near future, are selected as renewal ones. Replace priority was decided with special attention to safety concerns. A monitoring of aging condition by the regular maintenance activity is an important factor in selection of continuous using after the restart. In this report, renewal of the cooling system within refurbishment facilities in the JMTR is summarized.
Ide, Hiroshi; Hori, Naohiko; Gorai, Shigeru; Kusunoki, Tsuyoshi
JAEA-Review 2011-019, 24 Pages, 2011/06
JAEA-Review-2011-019.pdf:3.39MB
Japan Materials Testing Reactor (JMTR) is a testing reactor dedicated to the irradiation tests of materials and fuels. The reactor type of the JMTR is light water moderated and cooled tank type. It achieved first criticality in 1968. Operation was started in 1970. The JMTR had been being operated for 38 years from first criticality to the JMTR No.165 cycle finished. The restart of the JMTR has been strongly requested from various users as the only irradiation testing reactor in Japan. Finally, Japan Atomic Energy Agency (JAEA) decided the refurbishment and restart of the JMTR in December 2006, and the refurbishment works was started from FY 2007. This report summarized JMTR refurbishment and safety management during reactor shutdown.
Watahiki, Shunsuke; Asano, Norikazu; Hanawa, Yoshio; Gorai, Shigeru; Nishiyama, Yutaka; Tsuboi, Kazuaki
JAEA-Review 2010-019, 65 Pages, 2010/07
JAEA-Review-2010-019.pdf:7.25MB
JMTR secondary cooling system piping and a cooling tower were inspected from the view point of long term utilization before the renewal work for the secondary cooling system of the JMTR on FY 2008. As the result, it was confirmed that crack, swelling, and exfoliations in inner of piping lining, and decay and dryness of wood in the upper part of the cooling tower. From the result of this inspection some facilities and machinery were repaired or replaced from the view point of preventive maintenance.
Koike, Sumio; Gorai, Shigeru; Onoue, Ryuji; Otsuka, Kaoru
JAEA-Review 2010-007, 36 Pages, 2010/07
JAEA-Review-2010-007.pdf:5.0MB
Prior to the JMTR refurbishment, verification on reliability of the heat exchangers for primary cooling system was carried out to investigate an integrity of continuously use component. From a result of the significant corrosion, decrease of tube thickness, crack were not observed on the heat exchangers, and integrity of heat exchangers were confirmed. In the long terms usage of the heat exchangers, the maintenance based on periodical inspection and a long-term maintenance plan is scheduled.
Ebisawa, Hiroyuki; Hanakawa, Hiroki; Asano, Norikazu; Kusunoki, Hidehiko; Yanai, Tomohiro; Sato, Shinichi; Miyauchi, Masaru; Oto, Tsutomu; Kimura, Tadashi; Kawamata, Takanori; et al.
JAEA-Technology 2009-030, 165 Pages, 2009/07
JAEA-Technology-2009-030.pdf:69.18MB
The condition of facilities and machinery used continuously were investigated before the renewal work of JMTR on FY 2007. The subjects of investigation were reactor building, primary cooling system tanks, secondary cooling system piping and tower, emergency generator and so on. As the result, it was confirmed that some facilities and machinery were necessary to repair and others were used continuously for long term by maintaining on the long-term maintenance plan. JMTR is planed to renew by the result of this investigation.
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.
Gorai, Shigeru; Naka, Michihiro; Izumo, Hironobu; Nagao, Yoshiharu; Kawamura, Hiroshi
JAEA-Technology 2008-040, 17 Pages, 2008/06
JAEA-Technology-2008-040.pdf:1.82MB
Various projects for improvement of JMTR are being carried out with the aim to re-start in FY2011. In the projects, it is planned to improve the JMTR core management system to execute neutronic calculations. The JMTR core management system is based on SRAC code system on mainframe, it is expected to improve the JMTR core management system by means of conversion from SRAC code system to the newest SRAC2006 code system on UNIX. Therefore neutronic calculations for JMTR using SRAC2006 code system were executed in order to estimate applicability and effectiveness of SARC2006 code system to the JMTR core management system.
Gorai, Shigeru; Hanawa, Yoshio; Ebisawa, Hiroyuki; Oto, Tsutomu; Fukasaku, Akitomi
UTNL-R-0466, p.1_2_1 - 1_2_8, 2008/03
no abstracts in English
