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compoundsFrazer, D.*; Saleh, T. A.*; Matsumoto, Taku; Hirooka, Shun; Kato, Masato; McClellan, K.*; White, J. T.*
Nuclear Engineering and Design, 423, p.113136_1 - 113136_7, 2024/07
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)Nanoindentation based techniques can be employed on minute volumes of material to measure mechanical properties, including Young's modulus, hardness, and creep stress exponents. In this study, (U,Ce)O solid solutions samples are used to develop elevated temperature nanoindentation and nanoindentation creep testing methods for use on mixed oxide fuels. Nanoindentation testing was performed on 3 separate (Ux-1,Cex)O compounds ranging from x equals 0.1 to 0.3 at up to 800 
C: their Young's modulus, hardness, and creep stress exponents were evaluated. The Young's modulus decreases in the expected linear manner while the hardness decreases in the expected exponential manner. The nanoindentation creep experiments at 800 C give stress exponent values, n=4.7-6.9, that suggests dislocation motion as the deformation mechanism.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2024-007, 83 Pages, 2024/06
JAEA-Review-2024-007.pdf:5.56MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2022. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Investigation of environment induced property change and cracking behavior in fuel debris" conducted from FY2020 to FY2022. The present study focuses on "metallic debris", which is mainly composed of elements derived from fuel cladding and control rod sheaths. This is the final year of the three years project. The findings on their material properties are as follows. Six phases are precipitated in the metallic debris according to the state diagram of the Zr-Fe-B-C system. Under high-temperature oxidation conditions, an outer film composed mainly of Zr
Fe is formed on the surface. An inner layer oxide film is also formed according to the chemical composition of the matrix phase of the debris.
Sun, Y.*; Abe, Yuta; Muta, Hiroaki*; Oishi, Yuji*
Journal of Nuclear Science and Technology, 57(8), p.917 - 925, 2020/08
Times Cited Count：5 Percentile：44.39(Nuclear Science & Technology)Kitagaki, Toru; Ikeuchi, Hirotomo; Yano, Kimihiko; Brissonneau, L.*; Tormos, B.*; Domenger, R.*; Roger, J.*; Washiya, Tadahiro
Journal of Nuclear Science and Technology, 56(9-10), p.902 - 914, 2019/09
Times Cited Count：9 Percentile：64.25(Nuclear Science & Technology)Abe, Yuta; Otaka, Masahiko; Okazaki, Kodai*; Kawakami, Tomohiko*; Nakagiri, Toshio
Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 7 Pages, 2019/05
Since the hardness of fuel debris containing boride from B
C pellet in control rod is estimated to be two times higher as that of oxide, such as UO and ZrO, it is necessary to select the efficient and appropriate operation for removal of fuel debris formed in the severe accident of nuclear power plants. We focused on the characteristics of LIBS, an innovative rapid chemical in-situ analysis technology that enables simultaneous detection of B, O, and other metal elements in fuel debris. Simulated solidified melt specimens were obtained in the plasma heating tests (CMMR-0/-2, performed by JAEA) of simulated fuel assembly (ZrO is used to simulated UO pellet, other materials such as stainless steel, BC are same as fuel assembly). The LIBS signals of (B/O)/Zr ratio showed good linear relationship with Vickers hardness. This technique can be also applied as in-situ assessment tool for elemental composition and Vickers hardness of metal-oxide-boride materials.
Ueyama, Daichi*; Saito, Yuichi; Ishikawa, Norito; Omura, Takahito*; Semboshi, Satoshi*; Hori, Fuminobu*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 351, p.1 - 5, 2015/05
Times Cited Count：8 Percentile：52.78(Instruments & Instrumentation)Hoshino, Takanori; Kitagaki, Toru; Yano, Kimihiko; Okamura, Nobuo; Ohara, Hiroshi*; Fukasawa, Tetsuo*; Koizumi, Kenji
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
Tobita, Toru; Aizawa, Kazuya; Suzuki, Masahide; Iwase, Akihiro*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.331 - 339, 2004/12
Nevertheless, there is a possibility that 
-ray induces embrittlement more efficiently than fast neutron, the irradiation effect of -ray has not been fully clarified. Comparative experiments on irradiation hardening by 2.5MeV electron irradiation for the purpose of -ray irradiation and neutron irradiation were performed to the Fe-Cu model alloys. We obtained the dose dependence and the temperature dependence on irradiation induced hardening. The growth of Cu clusters with increase in irradiation dose was confirmed by the small angle neutron scattering measurements. Although the differences in hardening between electron and neutron irradiations were very small on a displacement-per-atom (dpa) basis, the electron irradiation hardening initiated slightly earlier than the neutron. The growth of Cu clusters with increase in irradiation dose was the principal cause of hardening. The present results suggested that, from an engineering point of view, both the -ray induced and neutron induced hardening can be well scaled by using dpa.
Futakawa, Masatoshi; Kogawa, Hiroyuki; Ishikura, Shuichi*; Kudo, Hisaaki*; Soyama, Hitoshi*
Journal de Physique, IV, 110, p.583 - 588, 2003/09
A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage, Split Hopkinson Pressure Bar (SHPB) tests impact tests were performed to impose the impact pressure to the interface between mercury and solid metals. In particular, the surface hardening treated samples: Kolsterising, some coatings are investigated. As results, it is confirmed that the pitting damage is suppressed by surface hardening treatments and relative hardness appeared to be a good correlating parameter on impact erosion resistance.
Futakawa, Masatoshi; Kogawa, Hiroyuki; Tsai, C.-C.*; Ishikura, Shuichi*; Ikeda, Yujiro
JAERI-Research 2003-005, 70 Pages, 2003/03
JAERI-Research-2003-005.pdf:12.08MB
A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the pitting damage at the high cycle impacts up to 10 million were given by the MIMTM. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the steady state with mass loss independently of testing machines and the incubation period is very dependent on materials and imposed pressures.
Futakawa, Masatoshi; Kogawa, Hiroyuki; Hino, Ryutaro; Date, Hidefumi*; Takeishi, Hiromasa*
International Journal of Impact Engineering, 28(2), p.123 - 135, 2003/02
JAERI is carrying out research & development to construct the a of spallation neutron source facility, which may bring us innovative science fields. A high power proton beam will be injected into a liquid mercury target to produce neutrons. The mercury vessel will consequently be subjected to the pressure waves generated by rapid thermal expansion. The pressure waves will propagate from the liquid mercury into the vessel solid metal, and back again. The pressure waves may induce erosion at the interface between the solid metal vessel and the liquid mercury under certain loading conditions, e.g. impact. In order to investigate the impact erosion damage due to the pressure wave, we have carried out impact experiments using a modified conventional split Hopkinson pressure bar apparatus on mercury filling a small chamber. Surface degradation in the form of many pits was observed and the ranking order of damage was found to be A6061
316SS@Inconel600Maraging steel, which is the same as that of hardness.
Koyama, Tomofumi*; Futakawa, Masatoshi; Kogawa, Hiroyuki; Ishikura, Shuichi*
Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2002) Koen Rombunshu, p.5 - 6, 2002/09
no abstracts in English
Morita, Kenji*; Ishino, Shiori*; Tobita, Toru; Chimi, Yasuhiro; Ishikawa, Norito; Iwase, Akihiro
Journal of Nuclear Materials, 304(2-3), p.153 - 160, 2002/08
Times Cited Count：13 Percentile：62.47(Materials Science, Multidisciplinary)To study the mechanism of irradiation embrittlement in pressure vessel alloys, we performed high energy ion irradiation experiments using FeCu model alloys. The dependences of Vickers hardness change by irradiation on ion fluence, irradiation temperature and Cu content were discussed.
Department of Hot Laboratories
JAERI-Tech 2002-050, 51 Pages, 2002/06
JAERI-Tech-2002-050.pdf:18.17MB
In Hamaoka Nuclear Power Station Unit-1 of Chubu Electric Power Company, a steam leak accident occurred with a pipe rupture. In order to investigate root cause of the pipe rupture, a task force was established within the Nuclear and Industrial Safety Agency (NISA). The JAERI was asked from NISA to cooperate as an independent neutral organization with NISA and perform an examination of the ruptured pipe. The JAERI examination group was formed at the Tokai Research Establishment and conducted some examinations of samples. In Dept. of Hot Laboratories, in order to respond the request of the investigation, the detailed program, various apparatuses, and technical staffs for the examinations are prepared. In this report, technical items in terms of contents of the examination, the used apparatuses, and techniques in three facilities in Dept. of Hot Laboratories (RFEF, RHL, and WASTEF) are summarized.
JAERI Working Group for Examination of the Ruptured Pipe at Hamaoka-1
JAERI-Tech 2002-045, 253 Pages, 2002/03
JAERI-Tech-2002-045.pdf:60.08MB
no abstracts in English
Seguchi, Tadao; Yagi, Toshiaki; Ishikawa, S.*; Sano, Y.*
Radiation Physics and Chemistry, 63(1), p.35 - 40, 2002/01
Times Cited Count：71 Percentile：96.20(Chemistry, Physical)no abstracts in English
JAERI Working Group for Examination of the Ruptured Pipe at Hamaoka-1
JAERI-Tech 2001-094, 60 Pages, 2001/12
JAERI-Tech-2001-094.pdf:13.99MB
no abstracts in English
Tobita, Toru; Suzuki, Masahide; Iwase, Akihiro; Aizawa, Kazuya
Journal of Nuclear Materials, 299(3), p.267 - 270, 2001/12
Times Cited Count：19 Percentile：82.56(Materials Science, Multidisciplinary)no abstracts in English
Shibata, Taiju; Ishihara, Masahiro; Takahashi, Tsuneo*; Motohashi, Yoshinobu*; Hayashi, Kimio
JAERI-Research 2001-024, 24 Pages, 2001/03
JAERI-Research-2001-024.pdf:6.25MB
no abstracts in English
Shibata, Taiju; Ishihara, Masahiro; Takahashi, Tsuneo*; Motohashi, Yoshinobu*
Proceedings of Asian Pacific Conference on Fracture and Strength '01(APCFS '01) and International Conference on Advanced Technology in Experimental Mechanics '01 (ATEM '01), p.894 - 898, 2001/00
no abstracts in English
