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Fujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Kato, Yoshiaki; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Hori, Junichi*; et al.
KURNS Progress Report 2019, P. 157, 2020/08
no abstracts in English
Shibata, Akira; Kato, Yoshiaki; Taguchi, Taketoshi; Futakawa, Masatoshi; Maekawa, Katsuhiro*
Nuclear Technology, 196(1), p.89 - 99, 2016/10
Times Cited Count:6 Percentile:49.29(Nuclear Science & Technology)Cladding material Zircaloy-4 is gradually replaced by M5 (Zr-Nb alloy) and other new Nb added Zirconium alloys which are expected to have long operating life. Corrosion tests on Zircaloy-4 and M5 were performed in various hydrogen concentrations in water to research corrosion properties of those alloys. Specimens were exposed under PWR conditions. Increase of oxide layer was analysed by weight gain and observation. Electro chemical impedance spectroscopy was performed to compare corrosion properties. And effect of dissolved hydrogen concentration on increase of oxide layer of M5 is smaller than that of Zircaloy-4. M5 is less affected by local uniformity of dissolved hydrogen concentration and is more suitable as PWR fuel cladding. Results of Electro chemical spectroscopy shows that structural significant difference existed in oxidizing reaction of Zircaloy-4 and M5.
Ishida, Takuya; Suzuki, Yoshitaka; Nishikata, Kaori; Yonekawa, Minoru; Kato, Yoshiaki; Shibata, Akira; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; et al.
KURRI Progress Report 2015, P. 64, 2016/08
no abstracts in English
Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko
JAEA-Technology 2015-031, 58 Pages, 2015/11
Technetium-99m (Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 (Mo) by (n, ) method, a parent nuclide of Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of Mo/Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR Hot Laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the -TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the Mo/Tc solution and the extracted Tc solution in the JMTR Hot Laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with Cs and Eu as alternative radionuclides of Mo and Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the Mo/Tc and Tc solutions using these devices. This report describes the results of those performance tests.
Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2014, P. 109, 2015/07
As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo by (n,) method ((n,)Mo production), a parent nuclide of Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the Tc solution extracted from Mo was evaluated. After the irradiation test of the high-density MoO pellets in the KUR, Tc was extracted from the Mo solution and the recovery rate of Tc achieved the target values. The Tc solution also got the value that satisfied the standard value for Tc radiopharmaceutical products by the solvent extraction method.
Shibata, Akira; Kato, Yoshiaki; Oishi, Makoto; Taguchi, Taketoshi; Ito, Masayasu; Yonekawa, Minoru; Kawamata, Kazuo
KAERI/GP-418/2015, p.151 - 165, 2015/05
The JMTR stopped its operation in 2006 for refurbishment. The reactor facilities have been refurbished from 2007. After refurbishment, JMTR Hot laboratory is expected to perform various post irradiation examinations. In this report, installations of experimental apparatuses and recent experimental method are introduced. (1) A nano-indenter with radius spherical indenter. Inverse analysis using FEM could presume material constants from load-depth curve of indentation. Mechanical properties of oxide layer of zirconium alloy and irradiated stainless steel will be analyzed. (2) Transmission Electron Microscope (TEM). TEM is capable of imaging at a significantly higher resolution than light microscopes or normal SEM. JAEA installed a TEM apparatus (JEOL JEM-2800) in JMTR Hot laboratory. The maximum magnification is 150,000,000 times. It can be operated from a remote location using a computer network. This contributes to the convenience of remote researchers and reducing the amount of exposure.
Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2013, P. 242, 2014/10
As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo-99 (Mo) by (n,) method ((n,)Mo production), a parent nuclide of Tc. In this study, preliminary irradiation tests were carried out with the high-density MoO pellets in the KUR and the Mo production amount was evaluated between the calculation results and measurement results.
Kurosawa, Makoto; Kato, Yoshiaki; Yonekawa, Minoru; Taguchi, Taketoshi
UTNL-R-0486, p.9_1 - 9_11, 2014/03
It has been irradiated in the concrete cell, the microscope lead cell, the lead cell for materials examinations and the iron cell and, in the JMTR Hot Laboratory Facilities, examines it after the irradiation such as fuel and nuclear reactor structure materials. I install a monitoring board for a concrete cell, a microscope lead cell, a lead cell for materials examinations and iron cells in the control room I watch concentration such as the minus number pressure in these each cell, the air absorption dose rate in the cell, the cover door opening and shutting indication and to control it. As for these monitoring boards, about 30 through 40 or more passed after an in-service start, and high aging decided to update it in consideration of the driving of approximately 20 years after JMTR re-operation because trouble by becoming it and outbreak of the malfunction were concerned about.
Watahiki, Shunsuke; Hanakawa, Hiroki; Imaizumi, Tomomi; Nagata, Hiroshi; Ide, Hiroshi; Komukai, Bunsaku; Kimura, Nobuaki; Miyauchi, Masaru; Ito, Masayasu; Nishikata, Kaori; et al.
JAEA-Technology 2013-021, 43 Pages, 2013/07
The number of research reactors in the world is decreasing because of their aging. On the other hand, the necessity of research reactor, which is used for human resources development, progress of the science and technology, industrial use and safety research is increasing for the countries which are planning to introduce the nuclear power plants. From above background, the Neutron Irradiation and Testing Reactor Center began to discuss a basic concept of Multipurpose Compact Research Reactor (MCRR) for education and training, etc., on 2010 to 2012. This activity is also expected to contribute to design tool improvement and human resource development in the center. In 2011, design study of reactor core, irradiation facilities with high versatility and practicality, and hot laboratory equipment for the production of Mo-99 was carried out. As the result of design study of reactor core, subcriticality and operation time of the reactor in consideration of an irradiation capsule, and about the transient response of the reactor to the reactivity disturbance during automatic control operation, it was possible to do automatic operation of MCRR, was confirmed. As the result of design study of irradiation facilities, it was confirmed that the implementation of an efficient mass production radioisotope Mo-99 can be expected. As the result of design study with hot laboratory facilities, Mo-99 production, RI export devised considered cell and facilities for exporting the specimens quickly was designed.
Taguchi, Taketoshi; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Nishikata, Kaori; Ishida, Takuya; Kawamata, Kazuo
UTNL-R-0483, p.10_5_1 - 10_5_13, 2013/03
JMTR focus on the activation method. By carrying out the preliminary tests using irradiation facilities existing, and verification tests using the irradiation facility that has developed in the cutting-edge research and development strategic strengthening business, as irradiation tests towards the production of Mo, we have been conducting research and development that can contribute to supply about 25% for Mo demand in Japan and the stable supply of radiopharmaceutical. This report describes a summary of the status of the preliminary tests for the production of Mo: Maintenance of test equipment in the facility in JMTR Hot Laboratory in preparation for research and development for the production of Mo in JMTR and using MoO pellet irradiated at Kyoto University Research Reactor Institute (KUR).
Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu; Watahiki, Shunsuke; Nagata, Hiroshi; Hanakawa, Hiroki; Naka, Michihiro; Kawamata, Kazuo; Yamaura, Takayuki; Ide, Hiroshi; et al.
JAEA-Technology 2011-031, 123 Pages, 2012/01
The number of research reactors in the world is decreasing because of their aging. However, the planning to introduce the nuclear power plants is increasing in Asian countries. In these Asian countries, the key issue is the human resource development for operation and management of nuclear power plants after constructed them, and also the necessity of research reactor, which is used for lifetime extension of LWRs, progress of the science and technology, expansion of industry use, human resources training and so on, is increasing. From above backgrounds, the Neutron Irradiation and Testing Reactor Center began to discuss basic concept of a multipurpose low-power research reactor for education and training, etc. This design study is expected to contribute not only to design tool improvement and human resources development in the Neutron Irradiation and Testing Reactor Center but also to maintain and upgrade the technology on research reactors in nuclear power-related companies. This report treats the activities of the working group from July 2010 to June 2011 on the multipurpose low-power research reactor in the Neutron Irradiation and Testing Reactor Center and nuclear power-related companies.
Ioka, Ikuo; Ishijima, Yasuhiro; Usami, Koji; Sakuraba, Naotoshi; Kato, Yoshiaki; Kiuchi, Kiyoshi
Journal of Nuclear Materials, 417(1-3), p.887 - 891, 2011/10
Times Cited Count:8 Percentile:53.37(Materials Science, Multidisciplinary)Fe-25Cr-35Ni EHP alloy was developed with conducting the countermeasure for IASCC. It is composed to adjust major elements, to remove harmful impurities and so on. The specimens were irradiated at 553 K for 25000h using JRR-3. The fluence was estimated to be 1.510n/m. Type 304SS was also irradiated as a comparison material. SSRT test was conducted in oxygenated water at 561 K in 7.7 MPa. The fracture mode of EHP alloy was ductile. IGSCC was not observed in the fracture surface. On the other hand, the fraction of IGSCC on the fracture surface of type 304 was about 70%. Microstructural evolution of EHP and type 304 after irradiation was examined by TEM. The defects induced by irradiation mostly consisted of black dots and frank loops in both specimens. No void was also observed in grain and grain boundary of both specimens. There was a little difference in microstructure after irradiation. It is believed that EHP alloy is superior to type 304 in irradiation.
Kaji, Yoshiyuki; Kondo, Keietsu; Aoyagi, Yoshiteru; Kato, Yoshiaki; Taguchi, Taketoshi; Takada, Fumiki; Nakano, Junichi; Ugachi, Hirokazu; Tsukada, Takashi; Takakura, Kenichi*; et al.
Proceedings of 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (CD-ROM), p.1203 - 1216, 2011/08
In order to investigate the effect of neutron dose rate on tensile property and irradiation assisted stress corrosion cracking (IASCC) growth behavior, the crack growth rate (CGR) test, tensile test and microstructure observation have been conducted with type 304 stainless steel specimens. The specimens were irradiated in high temperature water simulating the temperature of boiling water reactor (BWR) up to about 1dpa with two different dose rates at the Japan Materials Testing Reactor (JMTR). The radiation hardening increased with the dose rate, but there was little effect on CGR. Increase of the yield strength of specimens irradiated with the low dose rate condition was caused by the increase of number density of frank loops. Little difference of radiation-induced segregation at grain boundaries was observed in specimens irradiated by different dose rates. Furthermore, there was little effect on local plastic deformation behavior near crack tip in the crystal plasticity simulation.
Yonekawa, Minoru; Kato, Yoshiaki; Taguchi, Taketoshi; Sozawa, Shizuo
JAEA-Technology 2011-014, 16 Pages, 2011/06
The Japan Materials Testing Reactor (JMTR) is proceeding with the preparation for re-operation on 2011. The facilities and equipments in the hot laboratory had been improved from 2007 in order to deal with new requests for post irradiation examinations after re-operation of JMTR. Improvement of concrete cells and irradiation facilities are planned to be completed until the end of FY 2010 in order to carry out the post irradiated examination for research on high burnup fuel (maximum burn up: 110 GWd/t). In this report, improvement of concrete cells and irradiation facilities to handle the high burnup fuel in the hot laboratory is summarized.
Yonekawa, Minoru; Sozawa, Shizuo; Kato, Yoshiaki; Shibata, Akira; Nakagawa, Tetsuya; Kusunoki, Tsuyoshi
JAEA-Review 2010-049, 18 Pages, 2010/11
The hot laboratory (JMTR-HL) was founded to examine the objects mainly irradiated in the JMTR (Japan Materials Testing Reactor), 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 Computerized Tomography (CT) inspection 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 CT inspection system is able to observe a defect geometry closely and visually compared with a two dimensional system. In this paper, system design, production, installation and performance tests of an X-ray CT inspection system in a hot cell are reported. The X-ray CT inspection system consists of a computed tomography scanner, an X-ray source, a movable sample positioned, an X-ray detector, a collimator, and so on. After installation of apparatus, performance tests using irradiated fuel rods and radioisotopes were carried out to confirm the influence of rays and transmission X-ray property. By this development of the X-ray CT inspection system, it became possible to provide data with high technical value for post irradiation examination of high burn-up fuels and large type specimens.
Kato, Yoshiaki; Takada, Fumiki; Sozawa, Shizuo; Nakagawa, Tetsuya
JAEA-Testing 2009-008, 29 Pages, 2010/03
This report summarizes about the new equipment for the microstructural observation on the nuclear materials such as the structural material of light water reactor, which was installed in the JMTR Hot Laboratory. This experimental device, one of the PIE apparatuses, is useful to obtain the technical knowledge on the material degradation behavior by neutron irradiation damage and accumulate the data base for the integrity evaluation of nuclear power plant.
Sozawa, Shizuo; Nakagawa, Tetsuya; Omi, Masao; Hayashi, Koji; Iwamatsu, Shigemi; Kawamata, Kazuo; Kato, Yoshiaki; Kanazawa, Yoshiharu
JAEA-Technology 2009-069, 32 Pages, 2010/03
Refurbishment of the Japan Materials Testing Reactor (JMTR), which is recognized as one of important facilities in Japan for safety research, is in progress by the JAEA. In Extensive safety research of light-water reactor (LWR) fuels and materials under a contract with the Nuclear and Industrial Safety Agency of Ministry of Economy, Trade and Industry of Japan, the irradiation tests are planned in order to examine integrity of the LWR fuels and structure materials. For the irradiation tests of high burnup fuels and irradiated materials in the JMTR, modification of the hot laboratory facilities are needed, which are (1) strengthening JMTR hot-lab. cell-shielding, (2) the capsule assembling device, (3) domestic transportation cask, (4) fuel-rod center-hole processing device, (5) master-slave manipulators, (6) power manipulator, and (7) scanning electron microscope.
Taguchi, Taketoshi; Kato, Yoshiaki; Sozawa, Shizuo
JAEA-Technology 2009-029, 18 Pages, 2009/07
This report is concerned with the preparation of test-specimens for the post irradiation examination to contribute to the research on the aged deterioration and damage of the structure material of the light-water reactor, that consists of cutting, grinding, and the surface treatment of the irradiated material in the hot-cell at the JMTR Hot Laboratory. Two types of test-specimen preparation methods were developed for the electron beam backscatter diffraction (EBSD) observation and for the TEM observation. The specimens for those observations were sampled from fractions of the CT and the SSRT test specimens which were used in the irradiation-associated stress-corrosion cracking (IASCC) test. The technical difficulty in remote handling of the minimized specimens and of the fragile part where the crack progresses was overcome by a trial and error approach, and the adequate preparation technique for those tests was established.
Taguchi, Taketoshi; Kato, Yoshiaki; Takada, Fumiki; Omi, Masao; Nakagawa, Tetsuya
UTNL-R-0471, p.5_7_1 - 5_7_8, 2009/03
no abstracts in English
Kato, Yoshiaki; Miwa, Yukio; Takada, Fumiki; Omi, Masao; Nakagawa, Tetsuya
JAEA-Testing 2008-005, 48 Pages, 2008/06
This report is concerned with the EBSD-OIM analyzer for irradiated reactor materials, which was installed in the JMTR Hot Laboratory. As the first time in the world, it was installed in a hot cell as one of the examination facilities for irradiated nuclear materials and contributes to studies on IASCC (irradiation aided stress corrosion cracking) and IGSCC (irradiation grain boundary stress corrosion cracking). Its maintenance and operating experiences were described.