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Yano, Yasuhide; Sekio, Yoshihiro; Tanno, Takashi; Kato, Shoichi; Inoue, Toshihiko; Oka, Hiroshi; Otsuka, Satoshi; Furukawa, Tomohiro; Uwaba, Tomoyuki; Kaito, Takeji; et al.
Journal of Nuclear Materials, 516, p.347 - 353, 2019/04
Times Cited Count：22 Percentile：88.56(Materials Science, Multidisciplinary)9Cr-ODS steel claddings consisting of tempered martensitic matrix, showed prominent creep rupture strength at 1000 
C, which surpassed that of heat-resistant austenitic steels although creep rupture strength of tempered martensitic steels is generally lower than that of austenitic steels at high temperatures. The measured creep rupture strength of 9Cr-ODS steel claddings at 1000 C was higher than that from extrapolated creep rupture trend curves formulated using data at temperatures from 650 to 850 C. This superior strength seemed to be owing to transformation of the matrix from the 
-phase to the 
-phase. The transient burst strengths for 9Cr-ODS steel were much higher than those for 11Cr-ferritic/martensitic steel (PNC-FMS). Cumulative damage fraction analyses suggested that the life fraction rule can be used for the rupture life prediction of 9Cr-ODS steel and PNC-FMS claddings in the transient and accidental events with a certain accuracy.
Tada, Junichiro*; Nakashima, Hiroshi; Hayano, Ryugo*; Kobayashi, Hitoshi*; Asano, Yoshihiro*
Wakariyasui Hoshasen Butsurigaku; Kaitei 3-Han, 305 Pages, 2018/03
This book is an introduction to radiation physics. Under the concept of "linking physics of high school and radiation physics" for readers with high school graduation degree, we are doing simple commentary on the basis of qualitative explanation as much as possible. This book begins with "What is Radiation Physics", and consists of 12 chapters, including introductory special relativity, introductory quantum theory, structures of atoms and nuclei, radiations, radioactivity, interactions between radiation and matter, accelerators, radiation dose and so on.
Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count：23 Percentile：75.53(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the 
Ca + 
Pb, 
Ti + Pb, and Ca + 
Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Yano, Yasuhide; Tanno, Takashi; Sekio, Yoshihiro; Oka, Hiroshi; Otsuka, Satoshi; Uwaba, Tomoyuki; Kaito, Takeji
Nuclear Materials and Energy (Internet), 9, p.324 - 330, 2016/12
Times Cited Count：18 Percentile：81.79(Nuclear Science & Technology)Sato, Yutaka*; Kokawa, Hiroyuki*; Fujii, Hiromichi*; Yano, Yasuhide; Sekio, Yoshihiro
Metallurgical and Materials Transactions A, 46(12), p.5789 - 5800, 2015/12
Times Cited Count：18 Percentile：59.88(Materials Science, Multidisciplinary)Dissimilar friction stir welding (FSW) of an 11% Cr ferritic/martensitic stee (PNC-FMS) to 316-grade austenitic stainless steel was attempted with a view to its potential application to the wrapper tubes of next-generation fast reactors. The mechanical properties and microstructure of the resulting welds were systematically examined, which revealed that FSW produces a defect-free stir zone in which material intermixing is notably absent. That is, both steels are separately distributed along a zigzagging interface in the stir zone when PNC-FMS is placed on the retreating side, with the tool plunging at the butt line. This interface did not act as a fracture site during small-sized tensile testing of the stir zone. Furthermore, the microstructure of the stir zone was refined in both the PNC-FMS and 316 stainless steel sides, resulting in improved mechanical properties over the respective base material regions.
Yano, Yasuhide; Otsuka, Satoshi; Yamashita, Shinichiro; Ogawa, Ryuichiro; Sekine, Manabu; Endo, Toshiaki; Yamagata, Ichiro; Sekio, Yoshihiro; Tanno, Takashi; Uwaba, Tomoyuki; et al.
JAEA-Research 2013-030, 57 Pages, 2013/11
JAEA-Research-2013-030.pdf:48.2MB
It is necessary to develop the fast reactor core materials, which can achieve high-burnup operation improving safety and economical performance. Ferritic steels are expected to be good candidate core materials to achieve this objective because of their excellent void swelling resistance. Therefore, oxide dispersion strengthened (ODS) ferritic steel and 11Cr-ferritic/martensitic steel (PNC-FMS) have been respectively developed for cladding and wrapper tube materials in Japan Atomic Energy Agency. In this study, the effects of fast neutron irradiation on mechanical properties and microstructure of 9Cr-and 12Cr-ODS steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the CMIR-6 at temperatures between 420 and 835C to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures.
Yano, Yasuhide; Sato, Yutaka*; Sekio, Yoshihiro; Otsuka, Satoshi; Kaito, Takeji; Ogawa, Ryuichiro; Kokawa, Hiroyuki*
Journal of Nuclear Materials, 442(1-3), p.S524 - S528, 2013/09
Times Cited Count：16 Percentile：73.38(Materials Science, Multidisciplinary)Friction stir welding was applied to the wrapper tube materials, 11Cr-ferritic/martensitic steel, intended for fast reactors and defect-free welds were successfully produced. Then, the mechanical and microstructural properties of the friction stir welded steel were investigated. The hardness values of the stir zone were about 550 Hv, and they had hardly any dependence on the rotational speed, although they were much higher than that of the base material. However, tensile strengths and elongations of the stir zones were better at 298 K, compared to those of the base material. These excellent tensile properties were attributable to the fine grain formation during friction stir welding. A part of this study is the result of "Friction stir welding of the wrapper tube materials for Na fast reactors" carried out under the Strategic Promotion Program for Basic Nuclear Research by the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Ikeuchi, Hirotomo; Kondo, Yoshikazu*; Noguchi, Yoshihiro*; Yano, Kimihiko; Kaji, Naoya; Washiya, Tadahiro
Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.1349 - 1356, 2013/09
Sn conductors for ITER toroidal field coils in JapanTakahashi, Yoshikazu; Nabara, Yoshihiro; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Matsui, Kunihiro; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 23(3), p.4801504_1 - 4801504_4, 2013/06
Times Cited Count：11 Percentile：48.87(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) is the first to start the mass production of the TF conductors in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The height and width of the TF coils are 14 m and 9 m, respectively. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A circular multistage superconducting cable is inserted into a circular stainless steel jacket with a thickness of 2 mm. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and the cable is inserted into a round-in-round stainless steel jacket. It was observed that the cabling pitch of the destructive sample is longer than the original pitch at cabling. The JAEA carried out the tensile tests of the cable and the measurement of the cable rotation during the insertion to investigate the cause of the elongation. The cause of elongation was clarified and the results will be described in this paper.
Sato, Yutaka*; Kokawa, Hiroyuki*; Yano, Yasuhide; Sekio, Yoshihiro
Friction Stir Welding and Processing, 7, p.91 - 99, 2013/03
PNC-FMS is a newly developed 11Cr-ferritic/martensitic steel with good swelling resistance, designed for the wrapper tubes of fast reactors. In this study, friction stir welding (FSW) was attempted as a welding process of PNC-FMS because fusion welding of this steel significantly reduced mechanical properties through formation of brittle microstructure. FSW was applied to PNC-FMS at 100 to 300 rpm using Q60 tool, and defect-free welds were obtained. The stir zones had fine microstructure with ferrite and martensite, and the grain size and fraction of martensite increased with rotational speed. Since all welds were overmatched, all transverse tensile specimens were broken at the base material region. The tensile test of the stir zone clarified that the stir zone produced at 100 rpm exhibited higher strengths and elongation than the base material. This study showed that FSW at lower rotational speed produced the stir zone having better mechanical properties in PNC-FMS.
Hamada, Kazuya; Takahashi, Yoshikazu; Nabara, Yoshihiro; Kawano, Katsumi; Ebisawa, Noboru; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Saito, Toru*; Nakajima, Hideo; Matsuda, Hidemitsu*; et al.
Teion Kogaku, 47(3), p.153 - 159, 2012/03
The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA has constructed newly conductor manufacturing facility. Prior to starting conductor, JAEA manufactured a 760-m long Cu dummy conductor as process qualification of dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.
Amamoto, Ippei; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Shibayama, Atsushi*; Yano, Tetsuji*; Nakada, Masami; Okamoto, Yoshihiro
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.503 - 508, 2010/10
The main objective of this development is to recycle the purified eutectic medium of the pyroreprocessing, delaying its disposal for as long as possible. We have introduced the simple filtration method to remove the rare earth element (REE) particles which were formed due to the conversion of REE chlorides to phosphates. Here, the iron phosphate glass is used as a filtration medium for the removal of FP particles. However, some soluble FP such as compounds of alkali-metals, alkaline-earth metals, etc. still remain in the eutectic medium. This time around, on an experimental basis, the iron phosphate glass has been used as a sorbent instead, to remove the soluble FP. We have obtained some positive results and have intention to incorporate it into the spent electrolyte recycle process as a part of the FP separation and immobilization system.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Tanno, Takashi; Yano, Yasuhide; Oka, Hiroshi; Sekio, Yoshihiro; Otsuka, Satoshi; Kaito, Takeji; Tachi, Yoshiaki
no journal, ,
Ferritic/martensitic (F/M) steels are candidate for core material of fast reactors (FR) because of its superior swelling resistance. A 11Cr F/M steel (PNC-FMS) have been developed for wrapper tube and cladding tube for FR in JAEA. For demonstration of in-reactor performance and preparation of material strength standard, it is important to extend database on irradiation and thermal aging effects. In this work, ring tensile tests and hardness tests of PNC-FMS irradiated in Joyo up to 32.5 dpa at 455-835 C were carried out, and the results were compared with those of aging tests to clarify the irradiation effects exclusive of thermal aging effects. The UTS and hardness at RT of PNC-FMS irradiated at over 600 C tended to be lower than those of as-received and/or thermal aged ones. The facts indicate evident irradiation softening. On the other hand, PNC-FMS irradiated at 835 C was harder than that of aged one. Transformation during irradiation would be the cause.
Wakai, Eiichi; Iwamoto, Yosuke; Shibayama, Tamaki*; Sato, Koichi*; Toyota, Kodai; Onizawa, Takashi; Wakui, Takashi; Ishida, Taku*; Makimura, Shunsuke*; Nakagawa, Yuki*; et al.
no journal, ,
In the fields of accelerator target systems, nuclear power, aerospace, etc., radiation degradation of structural materials and equipment occurs, and therefore, the development of materials with high durability and excellent functions is expected. In order to create innovative materials that can be used in radiation fields, we are developing a new non-destructive inspection technique that can accurately measure the internal defects of various materials in radiation fields. As an innovative material, high-entropy alloys (HEA) are known for their high strength and ductility, and are expected to be used in various applications. In this talk, we will report on the construction of a measurement principle that enables multi-simultaneous measurements even in radiation fields, the status of HEA prototypes, and the status and progress of irradiation analysis of metals and other materials.
Shizukawa, Yuta; Sekio, Yoshihiro; Oka, Hiroshi; Tanno, Takashi; Yano, Yasuhide; Tachi, Yoshiaki; Otsuka, Satoshi; Kaito, Takeji
no journal, ,
In JAEA's Materials Monitoring Facility (MMF), various post-irradiation examination (PIEs) have been carried out on the long-life core, structural and absorber materials irradiated in the experimental fast reactor Joyo. The PIEs have revealed many important technological insights, i.e. the effects of irradiation on mechanical properties, microstructures, and physical properties of fast reactor materials such as modified austenitic steel, radiation-resistant ferritic steels including oxide dispersion strengthened (ODS) steel, B
C, and so on. The test specimens loaded and irradiated in material irradiation rig of Joyo can be tested in the hot-cell of MMF. In addition, the various samples could be machined from the wrapper tubes of driver and fuel test subassemblies irradiated in Joyo using by an electrical discharge machine (EDM). These samples can be characterized using the equipment such as tensile, miniature Charpy and TEM in the hot cell of MMF. In this presentation, we will introduce the details of feasible PIE equipment in the hot-cell of MMF, and examples of typical PIE data acquired by these equipment.
Osaka, Masahiko; Miwa, Shuhei; Kurosaki, Ken*; Yamanaka, Shinsuke*; Uno, Masayoshi*; Yamane, Yoshihiro*; Mimura, Hitoshi*; Yano, Toyohiko*
no journal, ,
Inert matrix fuel concept that is adaptable to the fast reactor cycle system was proposed. The concept has unique characteristics of a flexible management of minor actinides and effective utilization of beneficial materials in the nuclear cycle.
Tanno, Takashi; Yano, Yasuhide; Sekio, Yoshihiro; Oka, Hiroshi; Otsuka, Satoshi; Kaito, Takeji; Tachi, Yoshiaki
no journal, ,
Ferritic/martensitic (F/M) steels are candidate for core material of fast reactors (FR) because of its superior swelling resistance. A 11Cr F/M steel (PNC-FMS) have been developed for wrapper tube and cladding tube of demonstration FR in Japan Atomic Energy Agency. For demonstration of in-reactor performance and preparation of material strength standard, it is important to extend database on irradiation and thermal aging effects. In this work, ring tensile tests and hardness tests of PNC-FMS irradiated in Joyo up to 32.5 dpa at 455-835 C were carried out, and the results were compared with those of aging tests in order to clarify the irradiation effects exclusive of thermal aging effects. The UTS at RT of PNC-FMS irradiated at over 600 C tended to be lower than those of as-received and/or thermal aged ones. The hardness showed the same trend. But, the UTS and hardness test results showed that PNC-FMS irradiated at 835 C could be harder than that of aged one.
Sato, Yutaka*; Kokawa, Hiroyuki*; Yano, Yasuhide; Sekio, Yoshihiro
no journal, ,
no abstracts in English
Ikeuchi, Hirotomo; Yano, Kimihiko; Kaji, Naoya; Washiya, Tadahiro; Kondo, Yoshikazu*; Noguchi, Yoshihiro*
no journal, ,
no abstracts in English
