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Nakata, Toshiya; Komazaki, Shinichi*; Kono, Yutaka*; Tanigawa, Hiroyasu
Metallurgical Journal, LXIII(Sp.), p.146 - 150, 2010/08
The small punch (SP) test is one method of small specimen test technology. We constructed a model for finite element analysis (FEA) using the Ramberg-Osgood equation to try to estimate tensile properties from the SP test. The results showed that the SP curve obtained from previous experiments could be reproduced by FEA to the point where the necking behavior of SP specimens became prominent. It was found that the relationship between the Mises equivalent stress at the point giving the largest equivalent plastic strain, and the total strain based on the Ramberg-Osgood equation, in the SP specimens, agreed well with the true stress-true strain curve plotted from tensile test measurements, and could thus be used to evaluate the 0.2% proof stress, tensile strength and uniform elongation.
Tanigawa, Hiroyasu; Hirose, Takanori; Shiba, Kiyoyuki; Kasada, Ryuta*; Wakai, Eiichi; Serizawa, Hisashi*; Kawahito, Yosuke*; Jitsukawa, Shiro; Kimura, Akihiko*; Kono, Yutaka*; et al.
Fusion Engineering and Design, 83(10-12), p.1471 - 1476, 2008/12
Times Cited Count:78 Percentile:97.43(Nuclear Science & Technology)Reduced activation ferritic/martensitic steels (RAFMs) are recognized as the primary candidate structural materials for fusion blanket systems. F82H, which were developed and studied in Japan, was designed with an emphasis on high temperature properties and weldability. The database on F82H properties is currently the most extensive available among the existing RAFMs. The objective of this paper is to review the R&D status of F82H and to identify the key technical issues for the fabrication of an ITER Test Blanket Module (TBM) suggested by recent achievements in Japan.
Akasaka, Takeshi*; Kono, Takayoshi*; Takematsu, Yuji*; Nikawa, Hidefumi*; Nakahodo, Tsukasa*; Wakahara, Takatsugu*; Ishitsuka, Midori*; Tsuchiya, Takahiro*; Maeda, Yutaka*; Liu, M. T. H.*; et al.
Journal of the American Chemical Society, 130(39), p.12840 - 12841, 2008/10
Times Cited Count:78 Percentile:84.43(Chemistry, Multidisciplinary)We report here the results on single crystal X-ray crystallographic analysis of the Gd@C carbene adduct (Gd@C
(ad), Ad=adamantylidene). The Gd atom in Gd@C
(Ad) is located at an off-centered position near a hexagonal ring in the C2v-C
cage, as found for M@C
(M = Sc and La) and La@C
(Ad). Theoretical calculation also confirms the position of the Gd atom in the X-ray crystal structure.
Yonetani, Yoshiteru*; Maruyama, Yutaka*; Hirata, Fumio*; Kono, Hidetoshi
Journal of Chemical Physics, 128(18), p.185102_1 - 185102_9, 2008/05
Times Cited Count:20 Percentile:57.19(Chemistry, Physical)Ando, Masami; Li, M.*; Tanigawa, Hiroyasu; Grossbeck, M. L.*; Kim, S.-W.; Sawai, Tomotsugu; Shiba, Kiyoyuki; Kono, Yutaka*; Koyama, Akira*
Journal of Nuclear Materials, 367-370(1), p.122 - 126, 2007/08
Times Cited Count:19 Percentile:75.94(Materials Science, Multidisciplinary)Irradiation creep behavior of the F82H and several JLF-1 steels have been measured up to 5 dpa, using helium-pressurized creep tubes irradiated in HFIR. These tubes were pressurized with helium to hoop stress levels of 0 to 400 MPa for irradiation temperature. The results of F82H and JLF-1 with 200 MPa hoop stress showed small creep strains ( 0.15%) after irradiation. Irradiation creep rate in these steels is linearly dependent on the applied stress less than 200 MPa. However, at higher hoop stress level, the creep rate of them is nonlinear. The creep compliance coefficient for F82H and JLF-1 at 300
C is very small values. These data contribute to a part of materials database for ITER Test blanket design work.
Ando, Masami; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Jitsukawa, Shiro; Kono, Yutaka*; Koyama, Akira*; Li, M.*; Stoller, R. E.*
Nihon Kinzoku Gakkai-Shi, 71(7), p.559 - 562, 2007/07
Times Cited Count:0 Percentile:0.00(Metallurgy & Metallurgical Engineering)no abstracts in English
Nakata, Toshiya; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Komazaki, Shinichi*; Fujiwara, Mikio*; Kono, Yutaka*; Koyama, Akira*
Nihon Kinzoku Gakkai-Shi, 71(2), p.239 - 243, 2007/02
Times Cited Count:4 Percentile:32.45(Metallurgy & Metallurgical Engineering)no abstracts in English
Nakata, Toshiya; Komazaki, Shinichi*; Nakajima, Motoki*; Kono, Yutaka*; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Koyama, Akira*
Nihon Kinzoku Gakkai-Shi, 70(8), p.642 - 645, 2006/08
Times Cited Count:4 Percentile:33.53(Metallurgy & Metallurgical Engineering)no abstracts in English
Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
no abstracts in English
Kameo, Yutaka; Fujiwara, Asako; Watanabe, Koichi; Kono, Nobuaki; Nakashima, Mikio
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(3), p.187 - 193, 2005/09
no abstracts in English
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Dai-26-Kai Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Nenji Taikai Rombunshu, p.157 - 164, 2005/00
JAERI has conducted the analysis of domestic and the IAEA samples. JAERI is developing the analytical techniques to improve the analytical ability for the safeguards environmental samples. For bulk analysis, study is focused on the improvement of reliability of isotope ratio measurements by ICP-MS. New chemical separation techniques are under development and a desolvation module is introduced to reduce the polyatomic interferences. In particle analysis, the sample preparation procedure for SIMS method is modified to measure the U/
U and
U/
U ratios for individual particles. We are also developing fission track-TIMS method to measure uranium isotope ratios in particles of sub-micrometer size. A screening instrument of X-ray fluorescent analysis is equipped to measure elemental distribution on a swipe surface.
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of INMM 46th Annual Meeting (CD-ROM), 8 Pages, 2005/00
JAERI has been developing analytical techniques for ultra-trace amounts of nuclear materials in the environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis of the environmental swipe sample has been established as an ultra-trace analytical method of uranium and plutonium. In January 2003, JAERI was qualified as a member of the IAEA network analytical laboratories for environmental samples. Since then, JAERI has conducted the analysis of domestic and the IAEA samples. From Japanese fiscal year 2003, the second phase of the project was started for the development of advanced techniques, such as analyzing minor actinides and fission products as well as uranium and plutonium, particle analysis using fission-track technique, more efficient particle analysis using ICP-TOFMS and screening by X-ray fluorescent analysis. This paper deals with the progress in the development of the new techniques, applications and future perspective.
Takahashi, Masato; Magara, Masaaki; Sakurai, Satoshi; Kurosawa, Setsumi; Esaka, Fumitaka; Taguchi, Takuji; Takai, Konomi; Fukuyama, Hiroyasu; Lee, C. G.; Yasuda, Kenichiro; et al.
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, 8 Pages, 2002/09
Based on the strengthen safeguard program of the IAEA to detect undeclared nuclear activities, the method of precise and accurate isotope ratio determination for uranium and plutonium in the environmental samples (cotton swipes) has been developed at JAERI. The samples should be treated in clean environment in order to secure the analytical reliability by eliminating external contamination from the samples containing trace amount of uranium and plutonium. Since the measurement by ICP-MS is favorable to bulk analysis from view points of analytical capacity and operation simplicity, we have studied sample preparation procedures for the trace amount of uranium and plutonium to be applied to ICP-MS. Up to the present, interfering factors involved during analytical processes and the ICP-MS measurement of uranium and plutonium were examined. As a result, uranium and plutonium isotope measurement more than 100 pg and 100 fg, respectively, became possible at JAERI clean facility. At presentation, other progress in the development will be reported.
Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.
PNC TN8410 87-086VOL2, 944 Pages, 1986/09
Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.
PNC TN8410 87-086VOL1, 1037 Pages, 1986/09
A detailed design for a New Material Nitric Acid Recovery Evaporator was carried out with a plan to use it to replace an already constructed stainless steel Nitric Acid Recovery Evaporator at the Power Reactor and Nuclear Fuel Development Corporation's Tokai Works. Most of the original Evaporator's conditions such as compliance with applicable laws, standards, structure, treatment performance and operating conditions were maintained when designing the new machine. The material is titanium with the addition of 5% tantalum. The Evaporator was designed with an operational life expectance of 10 years. We have calculated that the new Evaporator will have sufficient strength (including a seismatic design) and have the same evaporative performance as the already constructed one. During design, we referred to the results of already completed basic designs (Phase 1) of New Material Nitric Acid Recovery Evaporators, design and production of small-scale test equipment units, and the development of successful joints between different materials. We also considered manufacturing, installation, trial runs, maintenance, and the specifications for materials used for manufacturing, installation, piping and operation of the new Evaporator.
Shibata, Hiromi*; Kono, Yutaka*; Sato, Takahiro; Okubo, Takeru; Yamazaki, Akiyoshi; Ishii, Yasuyuki; Yokoyama, Akihito; Koka, Masashi
no journal, ,
no abstracts in English
Chikada, Nobuyoshi*; Hayashi, Shigenari*; Ukai, Shigeharu*; Kono, Yutaka*; Otsuka, Satoshi; Kaito, Takeji
no journal, ,
The mechanistic study was carried out on high-temperature strength of 9Cr-ODS ferritic steel that has a duplex microstructure of tempered martensite and residual-alpha ferrite. Microstructure characterizations were performed by micro and nano-hardness tests and microstructure observations after normalizing and tempering. Resistance to tempering was shown to increase with volume fraction of residual-alpha ferrite. This result is consistent with creep rupture test result. Individual strength of tempered martensite and residual-alpha ferrite was estimated from nano-hardenss and inter-particle spacing. In the presentation, discussion will be performed on the mechanism of residual-alpha ferrite formation as well as the effect of residual-alpha ferrite on high-temperature strength improvement.
Ando, Masami; Tanigawa, Hiroyasu; Li, M.*; Nakata, Toshiya; Stoller, R.*; Kono, Yutaka*
no journal, ,
Irradiation creep of RAF/M steels has been recognized as one of the most important properties for engineering data due to the ITER test blanket structural design. The objective of this work is to examine an irradiation creep mechanism by using a microstructural observation in pressurized tubes of irradiated F82H and JLF-1. Irradiation was performed in the HFIR up to 5 dpa at 573 and 773 K. A small piece was cut from the center of each irradiated tube after diametral measurement. The microstructural examination with FIBed samples and replica films was carried out using a TEM. The creep strain for all steels at 573 and 773 K shows linear dependence on the applied hoop stress up to 250 MPa and
100 MPa, respectively. As results of extraction replica samples irradiated at 573 K, finer spherical precipitations were observed in highest hoop stress level. The detailed discussion will be presented along with the results of microstructure observation for irradiated specimens.
Nakata, Toshiya; Tanigawa, Hiroyasu; Ando, Masami; Komazaki, Shinichi*; Kono, Yutaka*
no journal, ,
Reduced activation ferritic/martensitic steels are the first candidate material for fusion reactor, and will be used as the structural materials of ITER test blanket modules (TBM). TBM will be assembled by welding various parts, it is important to be clearly mechanical properties of weldments to qualify TBM structure. In this paper, unirradiated mechanical properties of weldments, which is consisted of weld metal, heat affected zone (HAZ) and base metal region, obtained from TIG and EB welded F82H IEA-heat were evaluated by charpy impact and creep test. The creep tests were carried out at temperatures of 773-873 K and at stress levels of 150-260 MPa, with the specimens which include weld metal and HAZ region in the gage section. In these conditions, rupture time of weldments yield to about 100-1000 hours. The mechanism of these properties deterioration will be discussed based on the detailed analyses on microstructure changes.
Tanigawa, Hiroyasu; Nakata, Toshiya*; Kim, D.-H.*; Ando, Masami; Shiba, Kiyoyuki; Hirose, Takanori; Komazaki, Shinichi*; Kono, Yutaka*; Koyama, Akira*
no journal, ,
Reduced activation ferritic/martensitic steels (RAFMs) are recognized as the primary candidate structural materials for fusion blanket systems, as they have been developed based on massive industrial experience of ferritic/martensitic steel replacing Mo and Nb of high chromium heat resistant martensitic steels (such as modified 9Cr-1Mo) with W and Ta, respectively. F82H (Fe-8Cr-2W-V, Ta) is the RAFM which is designed with emphasis on high temperature property and weldablility. Fusion blanket system will be suffer from high temperature/high pressure of its coolant, heat flux of fusion plasma etc., which cause creep and fatigue load on blanket system. On the other hand, the current blanket system design have complicated structure to achieve its function, and require long weld to fabricate its structure. In this paper, unirradiated creep and fatigue properties of base metal and weldments of F82H will be reviewed, and critical issues for design will be discussed.