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Ishitsuka, Etsuo; Nagasumi, Satoru; Hasegawa, Toshinari; Kawai, Hiromi*; Wakisaka, Shinji*; Nagase, Sota*; Nakamura, Kento*; Yaguchi, Hiroki*; Ishii, Toshiaki; Nakano, Yumi*; et al.
JAEA-Technology 2024-008, 23 Pages, 2024/07
Five people from three universities participated in the 2023 summer holiday practical training with the theme of "Technical development on HTTR". The participants practiced the analysis of HTTR core, the analysis of behavior on loss of forced cooling test, the analysis of Iodine deposition behavior in primary cooling system and the feasibility study of energy storage system for HTGRs. In the questionnaire after this training, there were impressions such as that it was useful as a work experience and some students found it useful for their own research. These impressions suggest that this training was generally evaluated as good.
Ueda, Hiroshi*; Onoda, Shigeki*; Yamaguchi, Yasuhiro*; Kimura, Tsuyoshi*; Yoshizawa, Daichi*; Morioka, Toshiaki*; Hagiwara, Masayuki*; Hagihara, Masato*; Soda, Minoru*; Masuda, Takatsugu*; et al.
Physical Review B, 101(14), p.140408_1 - 140408_6, 2020/04
Times Cited Count:5 Percentile:27.03(Materials Science, Multidisciplinary)Nakano, Hiroko; Uehara, Toshiaki; Takeuchi, Tomoaki; Shibata, Hiroshi; Nakamura, Jinichi; Matsui, Yoshinori; Tsuchiya, Kunihiko
JAEA-Technology 2015-049, 61 Pages, 2016/03
In Japan Atomic Energy Agency, we started a research and development so as to monitor the Nuclear Plant Facilities situations during a severe accident, such as a radiation-resistant monitoring camera under a severe accident, a radiation resistant in-water transmission system for conveying the information in-core and a heat-resistant signal cable. As part of advance in a heat-resistant signal cable, we maintained to ex-core high-temperature and pressure water loop test equipment which can be simulated conditions of BWRs and PWRs for evaluation reliability and property of construction sheath materials. This equipment consists of Autoclave, water conditioning tank, water pump, high-pressure metering pump, preheater, heat exchanger and pure water purification equipment. This report describes the basic design and the results of performance tests of construction machinery and tools of ex-core high-temperature and pressure water loop test equipment.
Yamashita, Riyo; Hama, Katsuhiro; Takeuchi, Ryuji; Morikawa, Keita*; Hosoya, Shinichi*; Nakamura, Toshiaki*; Tanaka, Yumiko*
JAEA-Technology 2014-029, 118 Pages, 2014/09
This study is to gain a better understanding of mass transfer phenomena in the geological environment as well as to develop technologies for: measurement of the solute transport parameters, model construction, numerical analysis and validation of all those technologies based on the existing information. As part of solute transport study, laboratory experiments were planned to understand the influence of the geological characteristics of fracture on the solute transport parameters, also understand the differences in test results by the different sizes of the samples used for an experiment, and moreover to validate the parameters obtained by numerical analysis.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:191 Percentile:99.42(Physics, Nuclear)Transverse momentum distributions and yields for , and
in
collisions at
= 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different
collisions. We also present the scaling properties such as
and
scaling and discuss the mechanism of the particle production in
collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:10 Percentile:55.04(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to
collisions.
Nakamura, Takemi; Horiguchi, Hironori; Kishi, Toshiaki; Motohashi, Jun; Sasajima, Fumio; Kumada, Hiroaki*
Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.379 - 382, 2010/10
The clinical trials of BNCT have been conducted using JRR-4. The JRR-4 stopped in January 2008, because the graphite reflector was considerably damaged. For this reason, the specifications of graphite reflectors were renewal. All existing graphite reflectors of JRR-4 were changed by new graphite reflectors. The resumption of JRR-4 was carried out with new graphite reflectors in February 2010. We measured the characteristics of neutron beam at the JRR-4 Neutron Beam Facility. A cylindrical water phantom was put the gap for 1cm from the beam port. TLD and gold wire were inserted within the phantom when the phantom was irradiated. The results of the measured thermal neutron flux and the dose in water were compared with MCNP calculations. The calculated results showed the same tendency with the experimental results. These results are proceeding well and will be reported in full paper at July 2010.
Washiya, Tadahiro; Tayama, Toshimitsu; Nakamura, Kazuhito*; Yano, Kimihiko; Shibata, Atsuhiro; Nomura, Kazunori; Chikazawa, Takahiro*; Nagata, Masanobu*; Kikuchi, Toshiaki*
Journal of Power and Energy Systems (Internet), 4(1), p.191 - 201, 2010/02
Japan Atomic Energy Agency (JAEA) and Mitsubishi Materials Corporation (MMC) are developing the crystallization process for elemental technology of FBR fuel reprocessing. The uranium (U) crystallization process is a key technology for New Extraction System for TRU Recovery (NEXT) process that was evaluated as the most promising process for future FBR reprocessing. We had developed an innovative crystallizer and fabricated an engineering-scale crystallizer and have carried out continuous operation test to investigate the stability of the equipment at steady and non-steady state conditions by using depleted uranium. As for simulating typical failure events in the crystallizer, crystal accumulation and crystal blockage were occurred intentionally, and monitoring method and resume procedure were tried and selected in this work.
Shibata, Atsuhiro; Yano, Kimihiko; Kamiya, Masayoshi; Nakamura, Kazuhito; Washiya, Tadahiro; Chikazawa, Takahiro*; Kikuchi, Toshiaki*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 8(3), p.245 - 253, 2009/09
Behavior of Cs in U crystallization process of advanced aqueous reprocessing system was investigated with simulated dissolver solution. Beaker-scale U crystallization experiments were carried out with some simulated dissolver solutions. The results show that possibility of generation of CsNO,Cs
UO
(NO
)
or Cs-FP complex salt is small. Precipitation experiments of Cs-U(IV) complex salts were also carried out with nitrate solution of U(IV) and Cs. It was found that Cs-U(IV) complex salt was precipitated in higher acidity than 5 mol/dm
. It is suggested that Cs-Pu(IV) precipitates can be generated in the U crystallization process, under specific solution condition.
Yano, Kimihiko; Nakahara, Masaumi; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori; Nakamura, Kazuhito*; Tayama, Toshimitsu; Washiya, Tadahiro; Chikazawa, Takahiro*; Kikuchi, Toshiaki*; et al.
Proceedings of International Conference on Advanced Nuclear Fuel Cycle; Sustainable Options & Industrial Perspectives (Global 2009) (CD-ROM), p.143 - 150, 2009/09
Shibata, Atsuhiro; Kaji, Naoya; Nakahara, Masaumi; Yano, Kimihiko; Tayama, Toshimitsu; Nakamura, Kazuhito; Washiya, Tadahiro; Myochin, Munetaka; Chikazawa, Takahiro*; Kikuchi, Toshiaki*
Proceedings of International Conference on Advanced Nuclear Fuel Cycle; Sustainable Options & Industrial Perspectives (Global 2009) (CD-ROM), p.151 - 157, 2009/09
As a part of FaCT project, Japan Atomic Energy Agency has been developing a U crystallization process for advanced aqueous reprocessing technology in collaboration with Mitsubishi Materials Corporation. We have carried out experimental studies and obtained fundamental data. Continuous operation tests were also carried out by an engineering-scale crystallizer to confirm productivity of the equipment and to investigate non-steady state conditions. The requirements for the U crystallization process in the FaCT project could be achieved except DF of Cs. More detail investigation is under way to settle the process condition without Pu-Cs double salt formation.
Hayashi, Kimio; Nakagawa, Tetsuya; Onose, Shoji; Ishida, Takuya; Nakamichi, Masaru; Katsuyama, Kozo; Iwamatsu, Shigemi; Hasegawa, Teiji; Kodaka, Hideo; Takatsu, Hideyuki; et al.
JAEA-Technology 2009-007, 168 Pages, 2009/03
In-pile functional tests of breeding blankets have been planned by Japan Atomic Energy Agency (JAEA), using a test blanket module (TBM) which will be loaded in the International Thermonuclear Experimental Reactor (ITER). In preparation for the in-pile functional tests, JAEA has been being performed irradiation experiments of lithium titanate (LiTiO
), which is the first candidate of solid breeder materials for the blanket of the demonstration reactor (DEMO) under designing in Japan. The present report describes (1) results of a detailed design and trial fabrication tests of a dismantling apparatus for irradiation capsules which were used in irradiation experiments by the Japan Materials Testing Reactor (JMTR) of JAEA, and (2) results of a preliminary investigation of a glove box facility for post-irradiation examinations (PIEs). In the detailed design of the dismantling apparatus, datailed specifications and the installation methods were examined, based on results of a conceptual design and basic design. In the trial fabrication, cutting tests were curried out by making a mockup of a cutting component. Furthermore, a preliminary investigation of a glove box facility was carried out in order to secure a facility for PIE work after the capsule dismantling, which revealed a technical feasibility.
Shibata, Atsuhiro; Oyama, Koichi; Yano, Kimihiko; Nomura, Kazunori; Koyama, Tomozo; Nakamura, Kazuhito; Kikuchi, Toshiaki*; Homma, Shunji*
Journal of Nuclear Science and Technology, 46(2), p.204 - 209, 2009/02
Times Cited Count:7 Percentile:44.17(Nuclear Science & Technology)A new reprocessing system with 2-stage crystallization process has been developed. In the first stage of the system, U and Pu are recovered from dissolver solution by U-Pu co-crystallization. Laboratory scale experiments were carried out with U and Pu mixed solution and irradiated fuel dissolver solution to obtain fundamental data on U-Pu co-crystallization process. Pu co-crystallized with U, but crystallization yields of Pu were lower than those of U. FPs were separated from U and Pu by co-crystallization, and decontamination factors of Cs and Eu to U in crystal were over 100.
Nakamura, Takemi; Kumada, Hiroaki; Kishi, Toshiaki
Proceedings of 12th International Congress on Neutron Capture Therapy (ICNCT-12), p.535 - 538, 2006/10
no abstracts in English
Miyazaki, Itaru*; Shimizu, Toshiaki*; Shibata, Michihiro*; Kawade, Kiyoshi*; Furutaka, Kazuyoshi; Nakamura, Shoji; Sakane, Hitoshi
JNC TY8400 2005-002, 40 Pages, 2005/06
Accurate cross section data for the neutron capture of long-lived fission products (LLFP) are needed for developing a nuclear transmutation technology which reduces radioactive wastes by transmuting nuclides that have half-lives of as long as a few million years to other nuclides that have much shorter half-lives. There are some nuclides, whose cross sections cannot be measured in activation method. Utilization of prompt gamma-rays is expected to solve this problem. The aim of present study was twofold: (i) to measure emission probabilities of the high energy gamma-ray, up to 10MeV, emitted fromN(n, gamma)
N reaction, which are usually used as standards, in order to improve their accuracies and (ii) to develop a measurement method for neutron capture cross sections by using prompt gamma-rays. Emission probabilities of principal prompt gamma-rays from
N(n, gamma)
N reaction were determined with 0.2-0.9% errors. For ten nuclides,
Na,
Al,
55 Mn,
Ni,
Cu,
Pr,
W, and
capture cross sections were measured by using prompt gamma-rays and gamma-rays following b-decay. By comparing both cross section values, it was found that emission probabilities of prompt gamma-rays reported in the literatures were systematically larger than those inferred from the cross sections that were determined in activation methods. The cross section of a
Pd (n, gamma)
Pd reaction at thermal energy was measured. Considering transmutation of the nuclide, the cross section of
Pd(n, gamma), which is an isotope of palladium, is also necessary. A lower limit of the cross section was determined with 6% accuracy. Additionally, a method of estimating an upper limit was examined by noting similarity of nuclear structures to the neighboring nuclides. It was estimated that the observed lower limit of emission probabilities correspond to 79% of the cross section.
Yutani, Toshiaki*; Nakamura, Hiroo; Sugimoto, Masayoshi
JAERI-Tech 2005-036, 10 Pages, 2005/06
In the high flux region of the International Fusion Materials Irradiation Facility (IFMIF), the neutron irradiation damage for iron-based alloys will exceed 20 dpa/ year. An accurate specimen temperature measurement under a large amount of nuclear heating is a key issue but the change of heat transfer of gap between irradiation specimens and specimen holder during irradiation test is inevitable, if gap is filled with an inert gas and temperature is monitored by a thermocouple buried in the specimen holder. A solution to make heat transfer predictable is to fill the gap with a liquid metal (sodium or sodium-potassium alloy). An issue of compatibility between Reduced Activation Ferritic/Martensitic steels and the liquid metalsis addressed in this paper, and some recommendations for designing irradiation rig are presented, such as a purification control before filling liquid metals, or a careful selection of material of rig to avoid carbon mass transfer.
Nakamura, Hiroo; Riccardi, B.*; Loginov, N.*; Ara, Kuniaki*; Burgazzi, L.*; Cevolani, S.*; Dell'Ocro, G.*; Fazio, C.*; Giusti, D.*; Horiike, Hiroshi*; et al.
Journal of Nuclear Materials, 329-333(1), p.202 - 207, 2004/08
Times Cited Count:14 Percentile:65.28(Materials Science, Multidisciplinary)International Fusion Materials Irradiation Facility (IFMIF), being developed by EU, JA, RF and US, is a deuteron-lithium (Li) reaction neutron source for fusion materials testing. In the end of 2002, 3 year Key Element technology Phase (KEP) to reduce the key technology risk factors has been completed. This paper describes these KEP tasks results. To evaluate Li flow characteristics, a water and Li flow experiments have been done. To develop Li purification system, evaluation of nitrogen and tritium gettering materials have been done. Conceptual design of remote handling and basic experiment have been donde. In addition, safety analysis and diganostics design have been done. In the presentation, the latest design and future prospects will be also summarized.
Sugita, Nobutaka*; Nakajima, Masayuki*; Nakamura, Toshiaki*
JNC TJ7450 2004-002, 698 Pages, 2004/03
The research is carry out as part of Phase I (Surface-based Investigation Phase) in MIU (Mizunami Underground Research Laboratory) Project located on the MIU construction site in Mizunami City, Gihu Prefecture. The purpose of this research is to investigate the Physical property of rock in depyh from surface to the of 500m. Physical and mechanical properties of Mizunami Group and Toki granite have been obtained in our laboratory by using the core obtained from MIZ-1 bore hole.
Nakamura, Hiroo; Ida, Mizuho*; Sugimoto, Masayoshi; Yutani, Toshiaki*; Takeuchi, Hiroshi
Fusion Science and Technology, 41(3), p.845 - 849, 2002/05
This paper presents the design considerations on removal and control of tritium generated in liquid lithium target of International Fusion Materials Irradiation Facility (IFMIF). In the IFMIF, intense neutrons simulating fusion condition are produced by injecting deuterium beam with a maximum energy of 40 MeV and a maxim current of 250 mA into the liquid lithium flow with a speed of 20 m/s. Tritium is produced by direct reactions of the beam with the lithium. Total production rate is estimated to be about 10 g/year.As a reference method of the tritium removal, a cold trap with a swamping method is used. As an option, yttrium getter hot trap is considered. The concentration of hydrogen isotopes in the Li flow is detected by measuring their partial gas pressure which comes through a Nb or Nb-Zr membrane. To distinguish the isotopes from the other, a quadrupole mass spectrometer is used. The off-line sampling system is also used to measure the tritium concentration in the lithium.
Yutani, Toshiaki*; Nakamura, Hiroo; Sugimoto, Masayoshi; Takeuchi, Hiroshi
Fusion Science and Technology, 41(3), p.850 - 853, 2002/05
no abstracts in English