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Nishitani, Takeo; Sugie, Tatsuo; Morishita, Norio; Yokoo, Noriko*
Fusion Engineering and Design, 74(1-4), p.871 - 874, 2005/11
Times Cited Count：13 Percentile：65.42(Nuclear Science & Technology)no abstracts in English
Baba, Shinichi; Nemoto, Makoto*; Sozawa, Shizuo; Yamaji, Masatoshi*; Ishihara, Masahiro; Sawa, Kazuhiro
JAERI-Tech 2005-055, 157 Pages, 2005/09
JAERI-Tech-2005-055.pdf:19.06MB
The Japan Atomic Energy Research Institute (JAERI) has been carrying out the research on radiation damage mechanism of heat-resistant ceramics composite materials, as one of the subjects of the innovative basic research on high temperature engineering using the High Temperature Engineering Test Reactor (HTTR). A series of preliminary irradiation tests is being made using the Japan Materials Testing Reactor (JMTR). The present report describes results of post-irradiation examinations so far on specimens irradiated in the second and third capsule, designated 98M-41A and 99M-30A, to fast neutron fluences of 1.0
10
m
(E
1MeV) at temperatures of 973K-1173K and 1273K-1473K. The PIE were conducted as the fundamental statistics index of the diametral dimensions for irradiated specimen, irradiation induced dimensional change rate and thermal expansion rate.
Idesaki, Akira; Sugimoto, Masaki; Tanaka, Shigeru; Narisawa, Masaki*; Okamura, Kiyohito*; Ito, Masayoshi*
Journal of Materials Science, 39(18), p.5689 - 5694, 2004/09
Times Cited Count：7 Percentile：30.86(Materials Science, Multidisciplinary)Irradiation effect of 
-ray on polyvinylsilane (PVS), which is a liquid organosilicon polymer, was investigated and the optimum curing condition to synthesize a minute SiC product with radiation curing was discussed. Room temperature and liquid nitrogen temperature (77K) were examined as the irradiation temperature. In both cases, the cured PVS maintaining its formed shape could be obtained by -ray irradiation under vacuum, and the cured PVS in solid state at room temperature was obtained by irradiation with dose of above 3-4MGy. It was found that the efficiency of crosslinking in case of the irradiation at room temperature is higher than that in case of irradiation at 77K. The PVS injected into a mold was irradiated by -ray with dose of 3.6MGy at room temperature under vacuum, and pyrolyzed at 1273 K in Ar gas atmosphere. As a result, minute SiC products which had similar shapes to the mold and the sizes of 30-60
m were obtained.
Sumita, Junya; Nakano, Masaaki*; Tsuji, Nobumasa*; Shibata, Taiju; Ishihara, Masahiro
JAERI-Tech 2004-055, 25 Pages, 2004/08
JAERI-Tech-2004-055.pdf:4.25MB
Neutron irradiation remarkably reduces the thermal conductivity of graphite, and the reduced thermal conductivity is recovered by annealing effect if the graphite is heated above the irradiation temperature. Therefore, it is expected that the reduced thermal conductivity of graphite components in the HTGR could be recovered by the annealing effect in accidents, such as a depressurization accident. Then, an analytical investigation of the annealing effect on thermal performance of a HTGR core was carried. The analysis showed that the annealing effect reduces the maximum fuel temperature about 70
C, and it is important to introduce the annealing effect appropriately in the temperature analysis of the core components and reactor internals. In addition, an annealing test method was investigated to evaluate the effect quantitatively, and the test plan was made.
Nishitani, Takeo; Vayakis, G.*; Yamauchi, Michinori*; Sugie, Tatsuo; Kondoh, Takashi; Shikama, Tatsuo*; Ishitsuka, Etsuo; Kawashima, Hisato
Journal of Nuclear Materials, 329-333(Part2), p.1461 - 1465, 2004/08
Times Cited Count：16 Percentile：70(Materials Science, Multidisciplinary)no abstracts in English
Fusion Neutron Laboratory
JAERI-Review 2004-017, 163 Pages, 2004/07
JAERI-Review-2004-017.pdf:25.47MB
no abstracts in English
Onizawa, Kunio; Suzuki, Masahide
JSME International Journal, Series A, 47(3), p.479 - 485, 2004/07
In the structural integrity assessment of reactor pressure vessel, fracture toughness values are estimated by assuming that the radiation effect on fracture toughness is equivalent to that on Charpy properties. Therefore, it is necessary to establish the correlation between both properties especially on irradiation embrittlement. In this paper, we present the fracture toughness data obtained by applying the master curve approach that was adopted recently in the ASTM test method. Materials used in this study are five ASTM A533B class 1 steels and one weld metal. Neutron irradiation for Charpy-size specimens as well as standard Charpy-v specimens was carried out at the Japan Materials Testing Reactor. The shifts of the reference temperature on fracture toughness due to neutron irradiation are evaluated. Correlation between the fracture toughness reference temperature and Charpy transition temperature is established. Based on the correlation, the optimum test temperature for fracture toughness testing and the method to determine a lower bound fracture toughness curve are discussed.
Hoshiya, Taiji*; Takaya, Shigeru*; Ueno, Fumiyoshi; Nemoto, Yoshiyuki; Nagae, Yuji*; Miwa, Yukio; Abe, Yasuhiro*; Omi, Masao; Tsukada, Takashi; Aoto, Kazumi*
Transactions of the Materials Research Society of Japan, 29(4), p.1687 - 1690, 2004/06
JAERI and JNC have begun the cooperative research of evaluation techniques of structural material degradation in FBR and LWR, which based on magnetic and corrosion properties along grain boundaries. Magnetic method has been proposed as the one of the non-destructive detection techniques on the early stage of creep-damage before crack initiation for aged structural materials of FBRs. The effects of applied stress on natural magnetization were investigated on paramagnetic stainless steels having creep-damages. On the other hand, corrosion properties and magneto-optical characteristics of ion-irradiated stainless steels in the vicinity of grain boundaries were estimated by AFM and Kerr effect microscope, respectively. These degradations were induced by changes in characteristics in the vicinity of grain boundaries. It is found that the initial level of progressing process of damage can detect changes in magnetic and corrosion properties along grain boundaries of aged and degraded nuclear plants structural materials.
Yamakawa, Koji*; Chimi, Yasuhiro; Ishikawa, Norito; Iwase, Akihiro*
Journal of Alloys and Compounds, 370(1-2), p.211 - 216, 2004/05
Times Cited Count：1 Percentile：12.44(Chemistry, Physical)The migration of hydrogen in Pd-1at.% Fe-H and Pd-1at.% Ag-H alloys is investigated by electrical resistivity measurement around 50 K. The disordered hydrogen atoms are introduced by electron irradiation with 0.5 MeV electrons below 15 K. The disordered atoms order by migration of hydrogen atoms during the heating-up of the specimens. The recovery curves of electrical resistivity have two sub-stages for electron irradiated specimens and one stage for fast cooled specimens. The migration energy of hydrogen is obtained from the kinetic analysis of the resistivity change due to the ordering, using the cross-cut method for the electron irradiated specimen and fast cooled specimen. The obtained value of the migration energy for the low temperature stage is smaller than that for the high temperature stage. The value for the high temperature stage is similar to the energy for the case of fast cooling. The difference between the hydrogen atoms disordered by irradiation and that by fast cooling is discussed for Pd based alloys.
Ishitsuka, Etsuo; Kawamura, Hiroshi; Tanaka, Satoru*
JAERI-Conf 2004-006, 347 Pages, 2004/03
JAERI-Conf-2004-006.pdf:35.63MB
This report is the Proceedings of the Sixth International Energy Agency International Workshop on Beryllium Technology for Fusion. The workshop was held on December 2-5, 2003, at SEAGAIA in Miyazaki City, Japan with 69 participants who attended from Europe, the Russian Federation, Kazakhstan, Ukraine, China, the United States and Japan. The topics for papers were arranged into nine sessions; Status of beryllium study, Plasma and tritium interactions, ITER oriented issues, Neutron irradiation effects, Beryllide application, Disposal and recycling, Molten salt, Health and safety issues and Panel discussion. The issues in these topics were discussed intensively on the bases of 49 presentations. In the Panel discussion, the international collaboration for three topics, i.e., Neutron irradiation effects, Beryllide application, Recycling and Disposal, were discussed, and necessary items for the international collaboration were proposed.
Nemoto, Yoshiyuki; Hasegawa, Akira*; Sato, Manabu*; Abe, Katsunori*; Hiraoka, Yutaka*
Journal of Nuclear Materials, 324(1), p.62 - 70, 2004/01
Times Cited Count：38 Percentile：90.12(Materials Science, Multidisciplinary)In this study, stress-relieved specimens and recrystallized specimens of pure Mo and Mo-Re alloys (Re content=2,4,5,10,13 and 41wt%) were neutron irradiated up to 20dpa at various temperatures (681-1072K). On microstructure observation, sigma phase and chi phase precipitates were observed in all irradiated Mo-Re alloys. Voids were observed in all irradiated specimen, and dislocation loops and dislocations were observed in the specimens that were irradiated at lower temperatures. On Vickers hardness testing, all of the irradiated specimens showed hardening. Especially Mo-41Re were drastically embrittled after irradiation at 874K or less. From these results, authors discuss about relation between microstructure development and radiation hardening, embrittlement, and propose the most efficient Re content and thermal treatment for Mo-Re alloys to be used under irradiation condition.
Sugie, Tatsuo; Costley, A. E.*; Malaquias, A.*; Medvedev, A.*; Walker, C.*
Proceedings of 30th EPS Conference on Controlled Fusion and Plasma Physics (CD-ROM), 4 Pages, 2003/07
The main functions of the Divertor Impurity Monitor are to measure the parameters of impurities and isotopes of hydrogen in the divertor plasmas by using spectroscopic techniques in the wavelength range of 200-1000 nm. This system will have three different types of spectrometers; a) Visible survey spectrometers for impurity species monitoring. b) Filter spectrometers for two-dimensional measurements of particle influxes. c) High dispersion spectrometers for measuring the ion temperature and the particle energy distribution. The divertor region will be observed from the divertor-, the equatorial- and the upper-port. Optical components, such as mirrors, windows etc, mounted close to the plasma will experience higher levels of radiation due to neutron, gamma ray and/or particle irradiations than in present devices. Therefore, the materials of the components have to be carefully selected and mitigating methods adopted where possible. In addition, in-situ and remote calibration methods for diagnostic systems, which will be installed in the strong radiation field, are absolutely essential.
Tu, Z.; Kobayashi, Yasuhiko; Kiguchi, Kenji*; Watanabe, Hiroshi
Nuclear Instruments and Methods in Physics Research B, 206(1-4), p.591 - 595, 2003/05
Times Cited Count：0 Percentile：0.01(Instruments & Instrumentation)no abstracts in English
Nishitani, Takeo; Sugie, Tatsuo; Kasai, Satoshi; Kaneko, Junichi*; Yamamoto, Shin
Journal of Nuclear Materials, 307-311(Part2), p.1264 - 1267, 2002/12
Times Cited Count：23 Percentile：79.51(Materials Science, Multidisciplinary)no abstracts in English
Jitsukawa, Shiro; Tamura, Manabu*; Van der Schaaf, B.*; Klueh, R. L.*; Alamo, A.*; Petersen, C.*; Schirra, M.*; Spaetig, P.*; Odette, G. R.*; Tavassoli, A. A.*; et al.
Journal of Nuclear Materials, 307-311(Part1), p.179 - 186, 2002/12
Times Cited Count：160 Percentile：99.28(Materials Science, Multidisciplinary)Reduced activation ferritic/martensitic steel is the primary candidate structural material for ITER Test Blanket Modules and DEMOnstration fusion reactor because of its excellent dimensional stability under irradiation and lower residual activity as compared with the Ni bearing steels such as the austenitic stainless steels. In this paper, microstructural features, tensile, fracture toughness, creep and fatigue properties of a reduced activation martensitic steel F82H (8Cr-2W-0.04Ta-0.1C) are reported before and after irradiation, in addition to the design concept used for development of this alloy. A large number of collaborative test results including those generated under the IEA working group implementing agreements are collected and are used to evaluate the feasibility of use of F82H steel as one of the reference alloys. The effect of metallurgical variables on the irradiation hardening is reviewed and compared with the results obtained from irradiation experiments.
Ishii, Toshimitsu; Ooka, Norikazu; Hoshiya, Taiji; Kobayashi, Hideo*; Saito, Junichi; Niimi, Motoji; Tsuji, Hirokazu
Journal of Nuclear Materials, 307-311(Part.1), p.240 - 244, 2002/12
Times Cited Count：3 Percentile：23.41(Materials Science, Multidisciplinary)no abstracts in English
bulk samples and formation of columner defects on high-Tc supercoductorOkayasu, Satoru; Sasase, Masato; Hojo, Kiichi; Chimi, Yasuhiro; Iwase, Akihiro; Ikeda, Hiroshi*; Yoshizaki, Ryozo*; Kambara, Tadashi*; Sato, H.*; Hamatani, Yutaro*; et al.
Physica C, 382(1), p.104 - 107, 2002/10
Times Cited Count：28 Percentile：75.41(Physics, Applied)no abstracts in English
Iida, Toshiyuki*; Tanaka, Teruya*; Sato, Fuminobu*; Ochiai, Kentaro; Nishitani, Takeo
JAERI-Tech 2002-077, 38 Pages, 2002/09
no abstracts in English
Igarashi, Shinichi; Muto, Shunsuke*; Tanabe, Tetsuo*; Aihara, Jun; Hojo, Kiichi
Surface & Coatings Technology, 158-159, p.421 - 425, 2002/09
no abstracts in English
Nishitani, Takeo; Shikama, Tatsuo*; Sugie, Tatsuo; Kasai, Satoshi; Ishitsuka, Etsuo; Kawamura, Hiroshi; Kakuta, Tsunemi; Yagi, Toshiaki; Tanaka, Shigeru; Narui, Makoto*; et al.
JAERI-Research 2002-007, 149 Pages, 2002/03
JAERI-Research-2002-007.pdf:8.08MB
no abstracts in English
