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Co gamma irradiation test results with calculated resultsTakeda, Ryoma; Shibata, Hiroshi; Takeuchi, Tomoaki; Nakano, Hiroko; Seki, Misaki; Ide, Hiroshi
JAEA-Testing 2024-007, 33 Pages, 2025/03
JAEA-Testing-2024-007.pdf:1.63MB
Japan Materials Testing Reactor (JMTR) in Oarai Research and Development Institute of the Japan Atomic Energy Agency (JAEA) has been developing various reactor materials, irradiation techniques and instruments for more than 30 years. Among them, the development of self-powered neutron detectors (SPNDs) and gamma detectors (SPGDs) has been carried out, and several research results have been reported. In this report, we compare and verify these test results with the theoretical output results obtained by the calculation code created in the JAEA report (JAEA-Data/Code 2021-018). The comparison was made with the irradiation test results of SPGD, a cobalt-60 gamma irradiation facility. As a result, it was found that the calculation results reproduced the test results well when the emitter diameter was relatively small compared to the range of Compton scattered electrons by the gamma rays. On the other hand, when the emitter diameter is relatively large, the output current in the test results is only about half of the calculated output current. The self-shielding effect of the emitter may be one of the reasons for the difference in the emitter diameter, and a new formulation, such as incorporating the effect of self-shielding caused by a larger emitter diameter or a non-isotropic 
-ray field as a change in the mean electron range or mean minimum energy in the calculation code, is necessary. The new formulation is necessary.
Meigo, Shinichiro
Kasokuki, 21(4), p.333 - 344, 2025/01
For the study of material damage under the beam irradiation circumstance of accelerator-driven systems (ADS), the JAEA had planned to construct a TEF-T using J-PARC Linac 400-MeV proton beams and the LBE spallation target. The task force for evaluating partitioning and transmutation technology in the MEXT recommended that the facility be considered to maximize the advantages of using Linac to meet users' various needs. The proton irradiation facility, a successor of TEF-T, is planned to be constructed for 1) Material irradiation examinations, 2) Semiconductor soft-error examinations using spallation neutrons, 3) Medical RI production, and 4) Proton beam applications for space use. A user community was established in 2022 to incorporate user input as a more attractive facility. In this paper, the present design status of the facility is described.
Nakano, Hiroko; Fujinami, Kyoko; Yamaura, Takayuki; Kawakami, Jun; Hanakawa, Hiroki
JAEA-Review 2023-036, 33 Pages, 2024/03
JAEA-Review-2023-036.pdf:2.47MB
A practical training course using the JMTR (Japan Materials Testing Reactor) and other research infrastructures was held from November 29 to December 2 in 2021 for Asian young researchers and engineers. This course was adopted as International Youth Exchange Program in Science (SAKURA SCIENCE Exchange Program) which is the project of the Japan Science and Technology Agency, and this course aims to enlarge the number of high-level nuclear researchers/engineers in Asian countries which are planning to introduce a nuclear power plant, and to promote the use of facilities in future. In this year, from the viewpoint of preventing the spread of COVID-19 infection, it was decided to hold the event online. 53 young researchers and engineers joined the course from 6 countries. In FY2022, training programs with invitations were held due to the easing of restrictions on entry into Japan from overseas. 7 young researchers and engineers from4 Asian countries participated in the training from February 1 to 10, 2023. The common curriculum in the training course of FY2021 and FY2022 included lectures on nuclear energy, irradiation testing, safety management, JMTR decommissioning plan, etc. In the online session, conducted in FY2021, information exchange on the energy situation in each country was conducted. On-site training conducted in FY2022, included practical training on operation using simulations, environmental monitoring, etc. and facility tours of the JMTR, etc. Many participants could join the online training course, they created a diversity of expertise and made lively discussions during the information exchange. On-site training, while limited in number of participants, provided a good opportunity for personnel exchange through practical training and face-face communication. It is desirable to hold on-site training as long as circumstances permit. This report summarizes the training conducted in FY2021 and FY2022.
Hirano, Koichiro; Fukuda, Makoto*; Ezato, Koichiro*; Tokunaga, Kazutoshi*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.415 - 419, 2023/11
Tungsten is used in beam targets and experimental fusion reactor (ITER) divertors as a material with low activation, high thermal conductivity and high strength properties. Using a 3 MeV linac with negative hydrogen ion beam energy, multiple irradiation tests were conducted on tungsten materials meeting the ITER requirements, in which temperature changes of heating and cooling were repeatedly given at 5 Hz cycles. As a result, protrusions and cracks were observed on the surface of the test piece using SEM device, which were presumably caused by repeated expansion and contraction due to rapid pulse-like temperature change.
Ozawa, Takayuki; Hirooka, Shun; Kato, Masato; Novascone, S.*; Medvedev, P.*
Journal of Nuclear Materials, 553, p.153038_1 - 153038_16, 2021/09
Times Cited Count：8 Percentile：62.34(Materials Science, Multidisciplinary)To evaluate the O/M dependence of pore migration regarding fuel restructuring at the beginning of irradiation, we are developing BISON for MOX in cooperation with INL and have installed pore migration model considering vapor pressure of vapor species and thermal conductivity for MOX. The O/M dependence of fuel restructuring observed in MA-bearing MOX irradiation experiment in Joyo was evaluated by the 2-dimensional analyses. Four MA-bearing MOX pins with different O/M ratio and pellet/cladding gap size were irradiated in Joyo B14 experiment. Remarkable restructuring of stoichiometric MA-bearing MOX fuels was observed in PIE, and could be evaluated by considering the influence of O/M ratio on vapor pressure. Also, a central void assumes to move toward wide-gap side when the pellet eccentricity taking place, but 2-dimentional analyses on pellet transverse section revealed that the central void formation observed in PIE would be inconsistent with a direction of the pellet eccentricity.
Kuroda, Junya*; Manabe, Seiya*; Watanabe, Yukinobu*; Ito, Kojiro*; Liao, W.*; Hashimoto, Masanori*; Abe, Shinichiro; Harada, Masahide; Oikawa, Kenichi; Miyake, Yasuhiro*
IEEE Transactions on Nuclear Science, 67(7), p.1599 - 1605, 2020/07
Times Cited Count：4 Percentile：35.32(Engineering, Electrical & Electronic)Soft errors induced by terrestrial radiation in semiconductor devices have been of concern from the viewpoint of their reliability. Generally, to evaluate the soft error rates (SERs), neutron irradiation tests are performed at neutron facility. We have performed SER measurement for the 65-nm bulk SRAM and the FDSOI SRAM at RCNP in Osaka University and CYRIC in Tohoku University. In this study, we performed SER measurement for the same devices at BL10 in J-PARC MLF. The increasing rate of SER by reducing the supply voltage at J-PARC BL10 is larger than those obtained at RCNP and CYRIC. From PHITS simulation, the cause of this difference can be explained by the influence of the protons generated by neutron elastic scattering with hydrogen atoms in the package resin.
Shimazaki, Kazunori*; Kobayashi, Yuki*; Takahashi, Masato*; Imaizumi, Mitsuru*; Murashima, Mio*; Takahashi, Yu*; Toyota, Hiroyuki*; Kukita, Akio*; Oshima, Takeshi; Sato, Shinichiro; et al.
Proceedings of 40th IEEE Photovoltaic Specialists Conference (PVSC-40) (CD-ROM), p.2149 - 2154, 2014/06
The electrical performance of a glass-type space solar sheet (G-SSS) was demonstrated in space. G-SSS comprises InGaP/GaAs dual-junction and InGaP/GaAs/InGaAs triplejunction solar cells. It is lightweight solar generation sheet, less than 0.5 mm thick. It is mounted on the "HISAKI" (SPRINT-A) small scientific satellite, which was launched on September 14, 2013. The initial flight data were successfully acquired and this flight demonstration was a world-first experiment for G-SSS using III-V multi-junction thin-film solar cells. The cells demonstrated superior performance and the electrical outputs matched the flight prediction.
Shirasu, Noriko; Kuramoto, Kenichi*; Yamashita, Toshiyuki; Ichise, Kenichi; Ono, Katsuto; Nihei, Yasuo
Journal of Nuclear Materials, 352(1-3), p.365 - 371, 2006/06
Times Cited Count：4 Percentile：29.81(Materials Science, Multidisciplinary)To evaluate irradiation behavior of the ROX fuel, irradiation experiment was carried out using 20% enriched U instead of Pu. Three fuels were prepared; a single phase fuel of YSZ containing UO
(U-YSZ), two particle-dispersed fuels of U-YSZ particle in spinel or corundum matrix. The U-YSZ particles were prepared by crashing presintered U-YSZ pellets and by sieving them. These fuels were irradiated in Japan Research Reactor No.3 for 13 cycles, about 300 days. Though many cracks were observed in the pellets by X-ray photographs, significant appearance changes were not observed for all fuel pins. Distribution of typical FPs was analyzed by the scanning over the fuel pin. Non-volatile nuclide remained in the fuel pellet. On the other hand, a part of Cs moved to the gaps between the pellets and to the insulators. 
Cs and 
Cs showed different distributions at the plenum. Fuel pellets were taken out from fuel pins without bonding. Spinel decomposition and subsequent restructuring were not observed probably due to low irradiation temperature.
Yamada, Hirokazu*; Kawamura, Hiroshi; Tsuchiya, Kunihiko; Kalinin, G.*; Nagao, Yoshiharu; Takada, Fumiki; Nishikawa, Masahiro*
Journal of Nuclear Materials, 340(1), p.57 - 63, 2005/04
Times Cited Count：5 Percentile：34.88(Materials Science, Multidisciplinary)This study was performed to clear the effect of neutron re-irradiation on mechanical properties to welding material un-irradiated and irradiated stainless steel. The effect of re-irradiation to these weldaments were evaluated by tensile tests, metallographical observation and hardness test. The result of tensile tests shows that ultimate tensile strength of all joints specimen were almost similar, 0.2% yield strength and total elongation were depend on the irradiation damage and weldaments or not. Therefore, fracture mechanism was not change by re-irradiation. However, brittlement of material was depend on irradiation damage and the property of deformation was sensitive by the effect of irradiation damage or the effect of welding heat.
TiO
pebble bed from the core of JMTRIkeshima, Yoshiaki; Ishida, Takuya*; Tsuchiya, Kunihiko; Tomita, Kenji; Ebisawa, Hiroyuki; Magome, Hirokatsu; Nakamichi, Masaru*; Kitajima, Toshio; Kawamura, Hiroshi
JAERI-Tech 2005-005, 37 Pages, 2005/02
JAERI-Tech-2005-005.pdf:7.59MB
no abstracts in English
Baba, Shinichi; Yamaji, Masatoshi*; Shibata, Taiju; Ishihara, Masahiro; Sawa, Kazuhiro
JAERI-Tech 2005-002, 83 Pages, 2005/02
JAERI-Tech-2005-002.pdf:14.02MB
The innovative basic research concerns the association of basic and technology with high temperature irradiation environments. The direction of research involves novel and bold challenges both in nuclear and non-nuclear fields. The innovative basic research on high-temperature engineering is one of the key subjects using the HTTR as well as other research reactors. The aim of this paper is to describe the preliminary irradiated test conditions such as irradiated fluence, irradiated temperature and installed specimen on the capsules, and also to show the specifications and performances of the apparatus for Post/Ante Irradoation Experiment.
-ray irradiation experiments of collimator key components for the 3GeV-RCS of J-PARCKinsho, Michikazu; Ogiwara, Norio; Masukawa, Fumihiro; Takeda, Osamu; Yamamoto, Kazami; Kusano, Joichi
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1309 - 1311, 2005/00
It was success to develop the radiation resistant components using for beam collimator. Turbo molecular pump could be operated more than 15 MGy of ray irradiation dose. Stepping motor developed at JAERI could be operated with good performance in the ray dose of more than 70 MGy. PEEK sheathed cables and connector have kept good performance during ray irradiation more than the dose of 10 MGy. It was cleared that the function of the heat pipe disappeared at 30 kGy ray irradiation dose.
Yamashita, Toshiyuki
Seramikkusu, 39(10), p.817 - 821, 2004/10
no abstracts in English
Kinsho, Michikazu; Ogiwara, Norio; Wada, Kaoru*; Yoshida, Motoo*; Nakayasu, Tatsuo*; Yamato, Yukio*
Vacuum, 73(2), p.175 - 180, 2004/03
Times Cited Count：4 Percentile：20.10(Materials Science, Multidisciplinary)The turbo molecular pump which can be operated exposed to high radiation has been developing at JAERI and Osaka Vacuum Ltd., because it is planed to use this turbo molecular pump for the 3GeV-RCS of the J-PARC project. The goal of irradiation dose is 30 MGy because the cumulative energy dose due to radiation is approximately estimated to be on the order of 100 MGy for 30 years of the 3GeV-RCS operation. In order to know radiation damage of turbo molecular pump, gamma-ray irradiation experiment has been performed at JAERI. The turbo molecular pump could operate properly less than 3.5 MGy absorption dose under gamma-ray irradiation environment. Since the elongation of elastomer vacuum seals became small due to exposed to radiation, this radiation damage of elastomer seals causes leak. The turbo molecular pump components except the elasomer seals, for example motor coil, control sensor, and etc, have kept high performance more than 7 MGy absorption dose. The turbo molecular pump without elastomer seals has been developed and the irradiation test will be started form April.
Ito, Haruhiko; Ide, Hiroshi; Yamaura, Takayuki; Tsuji, Tomoyuki
JAERI-Review 2004-001, 39 Pages, 2004/02
JAERI-Review-2004-001.pdf:2.02MB
no abstracts in English
TiO
pebble bed under neutron irradiationKawamura, Hiroshi; Kikukawa, Akihiro*; Tsuchiya, Kunihiko; Yamada, Hirokazu*; Nakamichi, Masaru; Ishitsuka, Etsuo; Enoeda, Mikio; Ito, Haruhiko
Fusion Engineering and Design, 69(1-4), p.263 - 267, 2003/09
Times Cited Count：3 Percentile：25.25(Nuclear Science & Technology)no abstracts in English
Nishitani, Takeo; Shikama, Tatsuo*; Reichle, R.*; Hodgson, E. R.*; Ishitsuka, Etsuo; Kasai, Satoshi; Yamamoto, Shin
Fusion Engineering and Design, 63-64, p.437 - 441, 2002/12
Times Cited Count：14 Percentile：64.57(Nuclear Science & Technology)no abstracts in English
Shibata, Taiju; Kikuchi, Takayuki; Miyamoto, Satoshi*; Ogura, Kazutomo*; Ishigaki, Yoshinobu*
FAPIG, (161), p.3 - 7, 2002/07
no abstracts in English
Nishitani, Takeo; Shikama, Tatsuo*; Reichle, R.*; Sugie, Tatsuo; Kakuta, Tsunemi; Kasai, Satoshi; Ishitsuka, Etsuo; Yamamoto, Shin
Purazuma, Kaku Yugo Gakkai-Shi, 78(5), p.462 - 467, 2002/05
no abstracts in English
Nakamichi, Masaru; Akutsu, Hisashi*; Yamaguchi, Katsuyoshi*; Tsuchiya, Kunihiko; Kawamura, Hiroshi; Ito, Haruhiko
JAERI-Data/Code 2002-010, 288 Pages, 2002/03
JAERI-Data-Code-2002-010.pdf:35.19MB
no abstracts in English
