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Saijo, Tomoaki; Mizuta, Naoki; Hasegawa, Toshinari; Suganuma, Takuro; Shimazaki, Yosuke; Ishihara, Masahiro; Iigaki, Kazuhiko
JAEA-Technology 2024-002, 96 Pages, 2024/06
Nuclear-grade graphite is used for core components of High Temperature Engineering Test Reactor (HTTR) due to excellent heat resistant properties. The physical properties of this graphite change with temperature and neutron irradiation, as well as exhibit complex behavior such as irradiation deformation and creep deformation. Then, stress analysis code has been developed for the graphite. In previous study, the code has been used to evaluate the shutdown stress by residual strain that accumulates with neutron irradiation. However, the effects of change in physical properties such as Young's modulus and thermal expansion-coefficient on shutdown stress have not been fully understood. Therefore, an evaluation model based on a simplified beam model was developed to clarify the effects of changes in physical properties and complex deformations on stresses occurring during operation and reactor shutdown, and to contribute to the development of graphite structures with longer lifetimes. As an application example, the effects of changes on various physical properties on operational and shutdown stresses were clarified for graphite components in the temperature range from 600 to 800C.
Ishihara, Masahiro
Genshiryokuyo Tanso, Kokuen Zairyo; Kiso To Oyo, p.10 - 18, 2017/12
Books summarizing the basic contents of nuclear carbon and graphite materials are seen in overseas, however, there is no book describing the whole aspect of the materials in Japan. Therefore, we describe fundamental matters on the materials in a wide range from basic to application. Here, we include also technical information necessary for structural design and structural integrity evaluation of the materials used in the graphite-moderated high temperature helium gas-cooled reactor. This is an introduction useful for students and graduate students, researchers and engineers, and experts who want to learn the whole issues of the materials for high temperature gas-cooled reactor.
Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Komanome, Hirohisa*; Miura, Kuniaki*; Ishihara, Masahiro
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 6 Pages, 2017/04
After the accident at the Fukushima Dai-ichi (1F) Nuclear Power Plant (NPP), the Japanese Government referred to "Enhancement of instrumentation to identify the status of the reactors and PCVs", in the report of Japanese government to the IAEA ministerial conference in June 2011. In response to these provisions, a research and development of a monitoring system for NPPs situations during severe accidents started in November 2012. The objectives of the R&D are composed of radiation-resistant monitoring camera, radiation-resistant in-water transmission system, and heat-resistant signal cable. For all the three objectives, the elemental technologies have been already developed and now trial system are being fabricated and tested under simulated conditions of severe accidents. The results will enable us to determine the basic specifications of the systems and to provide the information about application limits for users.
Daido, Hiroyuki; Kawatsuma, Shinji; Kojima, Hisayuki; Ishihara, Masahiro; Nakayama, Shinichi
Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 8 Pages, 2017/00
Sanada, Yukihisa; Munakata, Masahiro; Mori, Airi; Ishizaki, Azusa; Shimada, Kazumasa; Hirouchi, Jun; Nishizawa, Yukiyasu; Urabe, Yoshimi; Nakanishi, Chika*; Yamada, Tsutomu*; et al.
JAEA-Research 2016-016, 131 Pages, 2016/10
By the nuclear disaster of Fukushima Daiichi Nuclear Power Station (FDNPS), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPS. After the nuclear disaster, airborne radiation monitoring using manned helicopter was conducted around FDNPS. In addition, background dose rate monitoring was conducted around Sendai Nuclear Power Station. These results of the aerial radiation monitoring using the manned helicopter in the fiscal 2015 were summarized in the report.
Tsuchiya, Kunihiko; Takeuchi, Tomoaki; Komanome, Hirohisa*; Miura, Kuniaki*; Araki, Masanori; Ishihara, Masahiro
Nihon Hozen Gakkai Dai-13-Kai Gakujutsu Koenkai Yoshishu, p.375 - 378, 2016/07
no abstracts in English
Yoshida, Masahiro*; Ishii, Kenji; Naka, Makoto*; Ishihara, Sumio*; Jarrige, I.*; Ikeuchi, Kazuhiko*; Murakami, Yoichi*; Kudo, Kazutaka*; Koike, Yoji*; Nagata, Tomoko*; et al.
Scientific Reports (Internet), 6, p.23611_1 - 23611_8, 2016/03
Times Cited Count:1 Percentile:10.95(Multidisciplinary Sciences)Sanada, Yukihisa; Mori, Airi; Ishizaki, Azusa; Munakata, Masahiro; Nakayama, Shinichi; Nishizawa, Yukiyasu; Urabe, Yoshimi; Nakanishi, Chika; Yamada, Tsutomu; Ishida, Mutsushi; et al.
JAEA-Research 2015-006, 81 Pages, 2015/07
By the nuclear disaster of Fukushima Daiichi Nuclear Power Station (NPS), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPP. These results of the aerial radiation monitoring using the manned helicopter in the fiscal 2014 were summarized in the report.
Osaki, Hirotaka; Shimazaki, Yosuke; Sumita, Junya; Shibata, Taiju; Konishi, Takashi; Ishihara, Masahiro
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05
For the design on the VHTR graphite components, it is desirable to employ graphite material with higher strength. IG-430 graphite has been developed as an advanced candidate for VHTR. However, the new developed IG-430 does not have enough databases for the design of HTGR. In this paper, the compressive strength (Cs) of IG-430, one of important strengths for design data, is statistically evaluated. The component reliability is evaluated based on the safety factors defined by the graphite design code, and the applicability as the VHTR graphite material is discussed. It was found that IG-430 has higher strength (about 11%) and lower standard deviation (about 27%) than IG-110 which is one of traditional graphites used for HTGR, because the crack in IG-430 would not easy to propagate rather than IG-110. Since fracture probability for IG-430 is low, the higher reliability of core-component will be achieved using IG-430. It is expected that IG-430 is applicable for VHTR graphite material.
Iwamoto, Hiroki; Nishihara, Kenji; Katano, Ryota*; Fukushima, Masahiro; Tsujimoto, Kazufumi
JAEA-Research 2014-033, 82 Pages, 2015/03
The effect of experiments using Transmutation Physics Experimental Facility (TEF-P) is analysed from the viewpoint of the reduction of uncertainties in reactor physics parameters (criticality and coolant void reactivity) of an accelerator-driven system (ADS). The analysis is conducted by the nuclear-data adjustment method using JENDL-4.0 on the assumption that ve types of reactor physics experiments (a total of 44 experiments) are performed in TEF-P: (1) criticality experiment, (2) lead void reactivity experiment, (3) reaction rate ratio experiment, (4) sample reactivity experiment, and (5) fuel replacement reactivity experiment. As the result, 1.0% of uncertainty in criticality is found to be reduced to approximately 0.4%, and effective experiments for the reduction of uncertainty in criticality and coolant void reactivity are shown to be fuel replacement reactivity experiments and lead void reactivity experiments, respectively. Although these effects depend largely on the composition and amount of minor-actinide (MA) fuels, it is found that a combination of different types of experiments and database of existing experiments is effective in reducing the uncertainties.
Awaludin, R.*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Herlina*; Mutalib, A.*; Kimura, Akihiro; Tsuchiya, Kunihiko; Tanase, Masakazu*; Ishihara, Masahiro
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1481 - 1483, 2015/02
Times Cited Count:9 Percentile:58.41(Chemistry, Analytical)In this study, the Mo adsorption and Tc elution mechanism were investigated using SEM-EDS to analyze the elemental composition of the material surfaces before Mo adsorption, after Mo adsorption and after Tc elution using saline solution. The results were compared with the value of adsorption capacity of the material to irradiated natural Mo and elution yield of Tc. From the changes of elemental composition in the surface, it was found that molybdate ions were adsorbed into the adsorbent by ion exchange with Cl ion in the material. On the other hand, it was also revealed that Tc can be eluted from the material column in TcO since oxidizing agent was needed in the elution process.
Kimura, Nobuaki; Takemoto, Noriyuki; Ooka, Makoto; Ishitsuka, Etsuo; Nakatsuka, Toru; Ito, Haruhiko; Ishihara, Masahiro
JAEA-Review 2012-055, 40 Pages, 2013/03
Training courses using JMTR and related facilities as advanced research infrastructures have been newly organized for domestic students, young researchers and engineers since FY2010 from a viewpoint of nuclear human resource development in order to support global expansion of nuclear power industry. In FY 2012, two courses were carried for foreign as well as Japanese young researchers and engineers in order to carry out effective practical training. For the foreigner course, 16 young researchers and engineers were joined from July 23rd to August 10th. For the Japanese course, total 35 young researchers and engineers were joined two courses from August 20th to August 31st and from September 3rd to September 14th. Lectures of these training courses were consisted from basics of nuclear energy to its application, especially for irradiation tests in Motrin this paper, results of these foreigners and Japanese training courses are reported.
Ishihara, Masahiro; Ishitsuka, Etsuo; Suzuki, Masahide
JAEA-Conf 2012-002, 179 Pages, 2012/12
Under the "Arrangement for Corporation in the field of peaceful uses of Nuclear Energy between the Japan Atomic Energy Agency (JAEA) and the Korean Atomic Energy Research Institute (KAERI)", the 2012 JAEA/KAERI Joint Seminar on Advanced Irradiation and PIE (post-irradiation examination) Technologies has been held at Mito, Japan from March 28 to 30, 2012. This triennial seminar is the seventh in series of bilateral exchange of irradiation and PIE technologies and research reactor management. Since the first joint seminar on the PIE Technology between JAERI (Japan Atomic Energy Research Institute, former agency of JAEA) and KAERI was held at JAERI Oarai Research Institute, Japan in 1992, the international cooperation program between JAEA and KAERI has been actively carried out in the field of neutron irradiation. At the fifth seminar in 2005 and sixth in 2008, the irradiation technology and the research reactor management fields were included, respectively, to the joint seminar, and it covers whole areas of irradiation using research reactors. In this seminar total 37 presentations were made in three technical sessions, which are "research reactor management", "advanced irradiation technology" and "post-irradiation examination technology", and active information exchange was done among participants. Papers or manuscripts presented in the 2012 JAEA/KAERI Joint Seminar on Advanced Irradiation and PIE Technologies are contained in the proceedings.
Tsuchiya, Kunihiko; Tanase, Masakazu*; Takeuchi, Nobuhiro*; Kobayashi, Masaaki*; Hasegawa, Yoshio*; Yoshinaga, Hideo*; Kaminaga, Masanori; Ishihara, Masahiro; Kawamura, Hiroshi
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 10 Pages, 2012/10
As one of effective uses of the JMTR, JAEA has a plan to produce Mo by (n, ) method, a parent nuclide of Tc. In case of Japan, the supplying of Mo depends only on imports from foreign countries. The R&D on production method of Mo -Tc has been performed with Japanese industrial users under the cooperation programs. The main R&D items for the production are (1) Fabrication of irradiation target such as the sintered MoO pellets, (2) Separation and concentration of Tc by the solvent extraction from Mo solution, (3) Examination of Tc solution for a medicine, and (4) Mo recycling from Mo generator and solution. In this paper, the status of the R&D is introduced for the production of Mo -Tc.
Ishihara, Masahiro; Kimura, Nobuaki; Takemoto, Noriyuki; Ooka, Makoto; Kaminaga, Masanori; Kusunoki, Tsuyoshi; Komori, Yoshihiro; Suzuki, Masahide
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 7 Pages, 2012/10
The JMTR has been utilized for fuel/material irradiation examinations of LWRs, HTGR, fusion reactor as well as for RI productions. The refurbishment of the JMTR was started from the beginning of JFY 2007, and finished in March 2011 as planned schedule. Unfortunately, at the end of the JFY 2010 on March 11, the Great-Eastern-Japan-Earthquake occurred, and functional tests before the JMTR restart were delayed by the earthquake. Moreover, a detail inspection found some damages such as small cracks in the concrete structure, ground sinking around the reactor building. Consequently, the restart will delay from June 2011. Now, the safety evaluation of the facility after the earthquake disaster is being carried out aiming at the restart of the JMTR. The renewed JMTR will be started from JFY 2012 and operated for a period of about 20 years until around JFY 2030. The usability improvement of the JMTR is also discussed with users as the preparations for re-operation.
Ishitsuka, Etsuo; Ishihara, Masahiro; Suzuki, Masahide
JAEA-Review 2012-030, 247 Pages, 2012/07
This report summarizes the documents presented in the Specialist Meeting on Mo Production by (n,) Method, which was held on March 9 to 10, 2012, at the Yurakucho Asahi Hall in Tokyo, hosted by Japan Atomic Energy Agency. The objective of the meeting is to exchange the information of current status, future plan for the Mo production, and to make a discussion of "How to cooperate" in each research and test reactors. There were 27 participants from Poland, Kazakhstan, Indonesia, Thailand, Malaysia, Netherlands, Korea and Japan. As a result of this meeting, it was recognized that to push forward the development of Mo production by (n,) method is necessary for the future steady supply of Mo. Moreover, an irradiation test using the high density MoO pellet developed by the Japan Atomic Energy Agency was proposed from a viewpoint of a merit for the common irradiation target in each research and test reactors.
Ishihara, Masahiro; Suzuki, Masahide
JAEA-Conf 2011-003, 297 Pages, 2012/03
This report is the Proceedings of the 4th International Symposium on Materials Testing Reactors hosted by Japan Atomic Energy Agency (JAEA). The 4th symposium was originally scheduled to be held INVAP in Argentina. However, the aftermath of volcanic explosion at Chili forced the symposium to change place. Total 111 participants attended from Argentina, Belgium, France, Germany, Indonesia, Malaysia, Korea, South Africa, Switzerland, the United State and Japan. This symposium addressed the general topics of "status and future plan of materials testing reactors", "advancement of irradiation technology", "expansion of industry use(RI)", "facility, upgrade, aging management", "new generation MTR", "advancement of PIE technology", "development of advanced driver fuel", and "nuclear human resource development(HRD) for next generation", and 39 presentations were made.
Tsuchiya, Kunihiko; Mutalib, A.*; Chakrov, P.*; Kaminaga, Masanori; Ishihara, Masahiro; Kawamura, Hiroshi
JAEA-Conf 2011-003, p.137 - 141, 2012/03
As one of effective uses of the JMTR, JAEA has a plan to produce Mo by (n,) method, a parent nuclide of Tc. In case of Japan, the supplying of Mo depends only on imports from foreign countries, the R&D on production method of Mo-Tc has been performed with foreign countries and Japanese industrial users under the cooperation programs. The main R&D items for the production are (1) Fabrication of irradiation target such as the sintered MoO pellets, (2) Separation and concentration of Tc by the solvent extraction from Mo solution, (3) Examination of Tc solution for a medicine, and (4) Mo recycling from Mo generator and solution. Especially, it is important to establish the separation and extraction methods in the item (2) and the experiments and information exchanges in some methods have been carried out under the international cooperation. In this paper, the status of the R&D is introduced for the production of Mo-Tc.
Longhurst, G. R.*; Tsuchiya, Kunihiko; Dorn, C.*; Folkman, S. L.*; Fronk, T. H.*; Ishihara, Masahiro; Kawamura, Hiroshi; Tranter, T. N.*; Rohe, R.*; Uchida, Munenori*; et al.
Nuclear Technology, 176(3), p.430 - 441, 2011/12
Times Cited Count:13 Percentile:68.51(Nuclear Science & Technology)Beryllium has important roles in nuclear facilities such as fission reactors and fusion reactors. Its neutron multiplication capability and low atomic weight make it very useful as a reflector in fission reactors. In both applications, the beryllium and the impurities in it become activated by neutrons transmutating to radionuclides, some of which are long-lived and difficult to dispose of. Also, gas production, notably helium and tritium, results in swelling, embrittlement, and cracking, which means that the beryllium must be replaced periodically, especially in fission reactors where dimensional tolerances must be maintained. It has long been known that neutron activation of inherent iron and cobalt in the beryllium results in significant Co activity. In 2001, it was discovered that activation of naturally occurring contaminants in the beryllium creates sufficient C and Nb to render the irradiated beryllium "Greater-Than-Class-C" for disposal in US radioactive waste facilities. In this paper we review the extent of the disposal issue, processes that have been investigated or considered for improving the disposability of irradiated beryllium, and approaches for recycling.
Takemoto, Noriyuki; Izumo, Hironobu; Hori, Naohiko; Ishitsuka, Etsuo; Ishihara, Masahiro
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 4 Pages, 2011/12
Establishment of a world network is proposed to achieve efficient facility utilization and provide high quality irradiation data by role sharing of irradiation tests with materials testing reactors in the world. As for the first step, mutual understanding among materials testing reactors is thought to be necessary. From this point, an international symposium on materials testing reactors (ISMTR) was held to construct the world network from 2008 every year, and a common understanding of world network has begun to be shared. The ISMTR-5 will be held on USA in 2012, and the ISMTR-6 will be held on Argentine in 2013.