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Takabe, Yugo; Otsuka, Noriaki; Fuyushima, Takumi; Sayato, Natsuki; Inoue, Shuichi; Morita, Hisashi; Jaroszewicz, J.*; Migdal, M.*; Onuma, Yuichi; Tobita, Masahiro*; et al.
JAEA-Technology 2022-040, 45 Pages, 2023/03
Because of the decommission of the Japan Materials Testing Reactor (JMTR), the domestic neutron irradiation facility, which had played a central role in the development of innovative nuclear reactors and the development of technologies to further improve the safety, reliability, and efficiency of light water reactors, was lost. Therefore, it has become difficult to pass on the operation techniques of the irradiation test reactors and irradiation technologies, and to train human resources. In order to cope with these issues, we conducted a study on the implementation of irradiation tests using overseas reactors as neutron irradiation sites as an alternative method. Based on the "Arrangement between the National Centre for Nuclear Research and the Japan Atomic Energy Agency for Cooperation in Research and Development on Testing Reactor," the feasibility of conducting an irradiation test at the MARIA reactor (30 MW) owned by the National Centre for Nuclear Research (NCBJ) using the temperature control system, which is one of the JMTR irradiation technologies, was examined. As a result, it was found that the irradiation test was possible by modifying the ready-made capsule manufactured in accordance with the design and manufacturing standards of the JMTR. After the modification, a penetration test, an insulation continuity test, and an operation test in the range of room temperature to 300C, which is the operating temperature of the capsule, were conducted and favorable results were obtained. We have completed the preparations prior to transport to the MARIA reactor.
Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Ide, Hiroshi
JAEA-Technology 2022-017, 113 Pages, 2022/08
Japan Materials Testing Reactor (JMTR) was decided as a one of decommission facilities in April 2017. The activation activity of radioactive materials remaining in the reactor facility was evaluated in order to submit the decommissioning plan to the Nuclear Regulation Authority. Total activation activity was 9.310 Bq after the permanent shutdown of reactor, 2.710 Bq after 21 years, 1.010 Bq after 40 years and 2.410 Bq after 100 years. The structure with high activation activity was the core structural materials in JMTR such as beryllium frame, aluminum reflector, etc., and the material was stainless steel, beryllium, etc. The ratio of nuclides to the total amount of activated radioactivity was highest in H-3 until about 40 years after the reactor shutdown, and then in Ni-63. For reference, the radioactivity level was classified based on the results of the obtained radioactivity concentration. The ratio of the weight of each radioactivity level to the total weight was 0.3-0.4% (10-13t) for L1, 0.0-0.4% (0-14t) for L2, 1.0-1.2% (32-39t) for L3 and 98.0-98.7% (about 3200t) for CL until 100 years after the reactor shutdown. It was found that those classified as CL account for more than 90% of the total. When treating and disposing of radioactive waste, evaluation will be carried out based on appropriate methods, including evaluation results of secondary pollutants.
Omori, Takazumi; Otsuka, Kaoru; Endo, Yasuichi; Takeuchi, Tomoaki; Ide, Hiroshi
JAEA-Review 2021-015, 57 Pages, 2021/11
The JMTR reactor facility was selected as a decommissioning one in the Medium/Long-Term Management Plan of JAEA Facilities formulated on April 1, 2017. Therefore, the decommissioning plan was submitted to Nuclear Regulation Authority on September 18, 2019, and the approval was obtained on March 17, 2021 after two amendments. Currently, preparations for decommissioning are underway. The JMTR reactor facility has been aged for more than 50 years since the first criticality in March 1968. However, some of the water piping systems has not been updated since its construction, and there is a possibility of pipe wall thinning due to corrosion, etc. Therefore, the integrity of the water piping was investigated for the facilities that circulate cooling water and pump radioactive liquid waste. In this investigation, the main circulation system of the reactor primary cooling system, the pool canal circulation system, the CF pool circulation system, the drainage system of the liquid waste disposal system, and the hydraulic rabbit irradiation system of the main experimental facility were measured for the pipe wall thickness using the Ultrasonic Thickness Measurement (UTM) method. These values satisfied the technical standards for research and test reactor facilities. No loss of integrity is expected to occur during the upcoming decommissioning period. In the future, we will periodically confirm that there is no wall thinning in the piping of the cooling water circulation and the water transmission system during the decommissioning period by using this result as basic data.
Kawamata, Takanori; Onuma, Yuichi; Hanakawa, Hiroki
JAEA-Review 2018-031, 33 Pages, 2019/02
As "Regulations on events to be reported by nuclear disaster prevention manager based on act on special measures concerning nuclear emergency preparedness" was revised and enfored in 2017, Nuclear operator emergency action plan at Oarai Research and Development Institute was reconsidered, and Emergency Action Level (EAL) in JMTR was newly set. In setting the EAL, characteristics of the JMTR and EAL in nuclear power reactors were considerd because the characteristics of research reactors are different in reactor types. This report shows the basic policy and the selection result of the EAL setting in the JMTR.
Nakamichi, Masaru*; Kawamura, Hiroshi
JAERI-Research 2005-015, 35 Pages, 2005/06
no abstracts in English
Department of JMTR
JAERI-Review 2004-029, 100 Pages, 2005/01
no abstracts in English
Department of JMTR
JAERI-Review 2003-041, 89 Pages, 2004/01
During the FY2002 (April 2002 to March 2003), the Japan Materials Testing Reactor (JMTR) was operated in three operation cycles for studies on the irradiation-assisted stress corrosion cracking (IASCC) of internal structures of light water reactors, development of the fusion blanket, basic materials research, radioisotope production, and so on. The reactor was twice subjected to unscheduled shutdowns, once due to an error signal of the control-rod drive mechanism and afterwards due to leakage of primary coolant. Recovery and corrective actions were taken properly, such as improvements in related facilities and revision of operation manuals. Besides, the beryllium reflector frames were replaced, which are internal structures of the JMTR. Concerning development on techniques for irradiation utilization, noticeable progress was made in an evaluation method of neutron and -ray heating rates of materials in JMTR irradiation, in development and installation of a monitoring and control system of specimen temperatures for IASCC irradiation examinations, and in successful performance tests by a post-irradiation crack-growth testing device, which brought a prospect of comparative studies between in-situ and post-irradiation examinations. In studies on the fusion blanket, a basic process was established for production of tritium breeder pebbles, and irradiation techniques were developed for in-pile functional tests of a simulated blanket module. In addition, joint seminars were held with the Korea Atomic Energy Research Institute (KAERI) on techniques for irradiation and post-irradiation examinations. The present report summarizes the JMTR operation and related technical development in the Department of JMTR during the FY2002.
Ito, Haruhiko; Homma, Kenzo; Itabashi, Yukio; Tabata, Toshio; Akashi, Kazutomo; Inaba, Yukio; Kumahara, Hajime; Takahashi, Kunihiro; Kitajima, Toshio; Yokouchi, Iichiro
JAERI-Review 2003-024, 76 Pages, 2003/10
no abstracts in English
JMTR Pressure Measurement Pipe Investigation Committee
JAERI-Review 2003-014, 117 Pages, 2003/03
On December 10、2002, the leak was found at the pressure measurement pipe attached to the exit pipe of No.1 filing pump of the refining system of a primary cooling system at JMTR in Oarai Research establishment JAERI. Investigation Committee for Water Leakage from Instrumentation Pipe in JMTR was established and organized by specialists from inside and outside JAERI on December 16 and its meeting was held in public 3 times by 6th January, 2003. They investigated the cause and countermeasures of cracks, and also investigated enhancement of safety management. This is the report on the cause and countermeasures of cracks and enhancement of safety management.
Department of JMTR
JAERI-Review 2003-009, 96 Pages, 2003/03
During the FY2001 (April 2001 to March 2002), the JMTR (Japan Materials Testing Reactor) was operated in 5 operation cycles (113 days) for irradiation studies on the IASCC of the LWR materials, development of fusion blanket materials, radioisotope productions, and so on. The total number of capsules and hydraulic rabbits irradiated were 105 and 59, respectively. Technology development programs were conducted in the following fields. As concerning to the IASCC studies, an advanced water control system and saturation temperature capsulesモ were developed and installed in the JMTR, and the performance tests were carried out. Also a crack growth testing device for irradiated specimens was developed and installed in the hot laboratories. An efficient recycle process of Li was developed for the production of pebble type tritium breeder material, and the properties of beryllides were examined, both for the development of fusion reactor blanket. This report summarizes these activities performed in the department of JMTR during the FY2001.
Nagao, Yoshiharu; Ishii, Tadahiko; Niimi, Motoji; Fujiki, Kazuo; Takahashi, Hidetake
JAERI-Review 2002-031, 119 Pages, 2002/11
The published reports on the research and development activities using the JMTR since 1971 to date have been surveyed by the search of literature database and questionnaire survey. This report compiles the title lists and abstracts of reports published by JAERI and survey the trend of the research and development in JAERI using JMTR.
Nagao, Yoshiharu; Ishii, Tadahiko; Takeda, Takashi; Fujiki, Kazuo
JAERI-Review 2002-007, 191 Pages, 2002/03
The published reports on the research activities using the JMTR since 1971 to date have been surveyed by the search of literature database and questionnaire survey. This report summarized the result of survey as the title lists by research categories.
Department of JMTR
JAERI-Review 2002-001, 86 Pages, 2002/02
During the FY2000 (April 2000 to March 2001), the JMTR (Japan Materials Testing Reactor) was operated in 6 operation cycles (130 days) for irradiation studies on the IASCC of the LWR materials, development of actinide contained uranium-hydride fuels, development of fusion blanket materials, and so on. The total number of capsules and hydraulic rabbits irradiated were 132 and 79, respectively.Technology development programs were conducted in the following fields. As concerning to the utilization of JMTR, a irradiation facility for the IASCC studies, irradiation capsules for RPV surveillance specimen and automatic temperature control system for irradiation capsules were developed.New efficient production process was developed for pebble type tritium breeder material for fusion reactor blanket, and tritium generation/recovery behavior under irradiation was investigated using pebble packed test piece.This report summarizes these activities performed in the department of JMTR during the FY2000.
Department of JMTR
JAERI-Review 2001-009, 80 Pages, 2001/03
no abstracts in English
Department of JMTR
JAERI-Review 2000-007, p.94 - 0, 2000/05
no abstracts in English
Nagao, Yoshiharu; Nakamichi, Masaru; Kawamura, Hiroshi
Journal of Nuclear Science and Technology, 37(Suppl.1), p.423 - 426, 2000/03
no abstracts in English
Shimakawa, Satoshi; Tabata, Toshio; Komukai, Bunsaku
JAERI-Data/Code 99-045, p.31 - 0, 1999/11
no abstracts in English
Department of JMTR
JAERI-Review 99-006, 79 Pages, 1999/03
no abstracts in English
Department of JMTR
JAERI-Review 99-005, 79 Pages, 1999/03
no abstracts in English
Department of JMTR
JAERI-Review 98-004, 77 Pages, 1998/02
no abstracts in English