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Saito, Shigeru; Suzuki, Kazuhiro; Obata, Hiroki; Dai, Y.*
Nuclear Materials and Energy (Internet), 34, p.101338_1 - 101338_9, 2023/03
Times Cited Count：2 Percentile：48.47(Nuclear Science & Technology)In this study, a post-irradiation examination of pure tungsten (W) and tantalum (Ta) specimens irradiated at the Swiss Spallation-Neutron Source is conducted. W is used as a potential candidate for a solid spallation-target material owing to its favorable properties. However, W also suffers from several disadvantages such as poor corrosion resistance to water coolant and irradiation embrittlement. To improve these properties, cladding technologies using Ta for W alloys have been developed. In the present study, we investigated the irradiation effects on two tungsten materials, poly-crystal W (W-Poly) and single-crystal W (W-Sin), along with pure polycrystalline Ta. The tensile-test results revealed that W-Poly exhibited almost no ductility after irradiation of 10.2-35.0 dpa. W-Sin was irradiated up to 10.2 dpa and demonstrated 6% of total elongation (TE). With regard to Ta, TE decreased based on the increase in irradiation, reaching almost zero at doses of more than 10.3 dpa.
Kobayashi, Taishi*; Fushimi, Tomokazu*; Mizukoshi, Hirofumi*; Motokawa, Ryuhei; Sasaki, Takayuki*
Langmuir, 38(48), p.14656 - 14665, 2022/12
Times Cited Count：2 Percentile：26.09(Chemistry, Multidisciplinary)no abstracts in English
Nakano, Hiroko; Fuyushima, Takumi; Tsuguchi, Akira*; Nakamura, Mutsumi*; Takeuchi, Tomoaki; Takemoto, Noriyuki; Ide, Hiroshi
JAEA-Technology 2022-007, 34 Pages, 2022/06
JAEA-Technology-2022-007.pdf:3.35MB
In order to investigate the phenomenon of stress corrosion cracking (SCC) for structural materials at the light water reactor (LWR), it is important to manage a water quality for simulating high-temperature and high-pressure water. Generally, dissolved hydrogen (DH) concentration in water loop has been controlled by the bubbling method of pure hydrogen gas or standard gas with high hydrogen concentration. However, it is necessary to equip the preventing hydrogen explosion in the area installed experimental apparatus. In general, in order to prevent accident by hydrogen, it is required to take measures such as limiting the amount of leakage, eliminating hydrogen, shutting off the power supply, and suppressing combustion before an explosion occurs. Thus, the dissolved hydrogen concentration control apparatus by electrolysis method has been developed which has two electrolysis cells to control DH concentration by electrolyzing water loop. In this study, small basic experimental devices were set up. The preliminary data were acquired regarding the simple performance of two electrolysis cells and the change of DH concentration in circulation. Based on the preliminary data, the dissolved hydrogen concentration control apparatus was designed to be connected to the high-temperature and high-pressure water loop test equipment. This report describes the test results with the small basic experimental devices for the design of the dissolved hydrogen concentration control apparatus.
Li
TiO
(x = 0.13) studied by quasielastic neutron scatteringMatsuura, Masato*; Fujiwara, Yasuyuki*; Moriwake, Hiroki*; Ohara, Koji*; Kawakita, Yukinobu
Physical Review B, 104(9), p.094305_1 - 094305_7, 2021/09
Times Cited Count：5 Percentile：42.31(Materials Science, Multidisciplinary)
GeP
S
Yajima, Takeshi*; Hinuma, Yoyo*; Hori, Satoshi*; Iwasaki, Rui*; Kanno, Ryoji*; Ohara, Takashi; Nakao, Akiko*; Munakata, Koji*; Hiroi, Zenji*
Journal of Materials Chemistry A, 9(18), p.11278 - 11284, 2021/05
Times Cited Count：19 Percentile：79.98(Chemistry, Physical)Yoshigoe, Akitaka
Hoshako, 32(4), p.185 - 198, 2019/07
Synchrotron radiation photoelectron spectroscopy is a beneficial technique for precise analysis of chemical states of solid surfaces. Owing to its high luminosity, it ensures availability of termed synchrotron radiation real-time photoelectron spectroscopy which enables "
" observation of chemical reactions with gas molecules occurring at surfaces. In this review, oxygen adsorption reactions in the oxidation of silicon single crystal surfaces are focused. Through the demonstration of our research, the usefulness of synchrotron radiation real-time photoelectron spectroscopy to study molecular adsorption reactions at solid surfaces is briefly described and the future perspective would also be shown.
Sugiyama, Jun*; Umegaki, Izumi*; Nozaki, Hiroshi*; Higemoto, Wataru; Hamada, Koji*; Takeshita, Soshi*; Koda, Akihiro*; Shimomura, Koichiro*; Ninomiya, Kazuhiko*; Kubo, Kenya*
Physical Review Letters, 121(8), p.087202_1 - 087202_5, 2018/08
Times Cited Count：18 Percentile：73.84(Physics, Multidisciplinary)Sakauchi, Hitoshi; Kikuchi, Yuki; Imaizumi, Haruki; Fukui, Yasutaka
Dekomisshoningu Giho, (57), p.34 - 42, 2018/03
OWTF (Oarai Waste Reduction Treatment Facility) is constructed for volume reduction processing and stabilization treatment of radioactive solid waste, which generate from hot facilities in Oarai Research and Development Center of Japan Atomic Energy Agency, using in-can type high frequency induction heating by remote control. In this report, we describe the outline of OWTF under construction and treatment technologies, in which incinerating and melting.
Kumada, Takayuki
Kagaku No Yoten Shirizu, 20, P. 71, 2017/06
no abstracts in English
Department of Research Reactor and Tandem Accelerator
JAEA-Review 2016-025, 101 Pages, 2016/12
JAEA-Review-2016-025.pdf:7.86MB
The JAEA-Tokai tandem accelerator complex has been used in various research fields such as nuclear science and material science by researchers not only of JAEA but also from universities, research institutes and industrial companies. This annual report covers developments of accelerators and research activities carried out using the tandem accelerator and superconducting booster from April 1, 2013 to March 31, 2014. Thirty-one summary reports were categorized into seven research/development fields:(1) accelerator operation and development, (2) nuclear structure, (3) nuclear reaction, (4) nuclear chemistry, (5) nuclear theory, (6) atomic physics and solid state physics (7) radiation effects in materials. This report also lists publications, meetings, personnel, committee members, cooperative researches and common use programs.
Sakauchi, Hitoshi; Sato, Isamu*; Donomae, Yasushi; Kitamura, Ryoichi
JAEA-Technology 2015-059, 352 Pages, 2016/03
JAEA-Technology-2015-059.pdf:51.53MB
OWTF (Oarai Waste Reduction Treatment Facility) is constructed for volume reduction processing and stabilization treatment of 
solid waste, which was generated from hot facilities in Oarai Research and Develop Center of Japan Atomic Energy Agency, using in-can type high frequency induction heating by remote control. This report describes corroborative tests, in which incinerating and melting performance for OWTF is confirmed with a full-scale testing furnace. We have been carrying out the tests of incinerating and melting treatment with some kinds of simulated wastes, such as enclosure form of radioactive wastes, material and articles.
-tetrafluoroethylene) films using different mediaNuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.
Transactions of the Materials Research Society of Japan, 40(4), p.359 - 362, 2015/12
The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion-conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 
m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV 
Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60
C. A medium was a mixture of water (HO) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the HO content became higher, and reached a maximum in pure HO. These results can be explained by considering the well-known Trommsdorff effect, in which poor solubility of the grafted polymer in polar media leads to an increased polymerization rate probably due to a lower termination rate.
emission reduction of active carbon recycling energy system for ironmaking by modeling with Aspen PlusSuzuki, Katsuki*; Hayashi, Kentaro*; Kurihara, Kohei*; Nakagaki, Takao*; Kasahara, Seiji
ISIJ International, 55(2), p.340 - 347, 2015/02
Times Cited Count：19 Percentile：65.27(Metallurgy & Metallurgical Engineering)Use of the Active Carbon Recycling Energy System in ironmaking (iACRES) has been proposed for reducing CO emissions. To evaluate the performance of iACRES quantitatively, a process flow diagram of a blast furnace model with iACRES was developed using Aspen Plus, a chemical process simulator. CO emission reduction and exergy analysis were performed by using mass and energy balance obtained from simulation results. The following CO reduction methods were evaluated as iACRES: solid oxide electrolysis cells (SOEC) with CO capture and separation (CCS), SOEC without CCS, and a reverse water-gas shift reactor powered by a high-temperature gas-cooled reactor. iACRES enabled CO emission reduction by 3-11% by recycling CO and H, whereas effective exergy ratio decreased by 1-7%.
Hayashi, Kentaro*; Suzuki, Katsuki*; Kurihara, Kohei*; Nakagaki, Takao*; Kasahara, Seiji
Tanso Junkan Seitetsu Kenkyukai Saika Hokokusho; Tanso Junkan Seitetsu No Tenkai, p.27 - 41, 2015/02
Applying Active Carbon Recycling Energy System to ironmaking (iACRES) process is a promising technology to reduce coal usage and CO emissions. To evaluate performance of iACRES quantitatively, a process flow diagram of the blast furnace model with iACRES was developed using Aspen Plus. CO emission reduction and exergy analysis was predicted by using mass and energy balance obtained from the simulation results. The followings were investigated as iACRES: solid oxide electrolysis cells (SOEC) with CO capture and separation (CCS), SOEC without CCS, and a reverse water-gas shift reactor as the a CO reduction reactor powered by a high-temperature gas-cooled reactor. iACRES could provide CO emission reductions of 3-11% by recycling CO and H, whereas the effective exergy ratio decreased by 1-7%.
Mimura, Hitoshi*; Yamagishi, Isao
Zeoraito, 31(4), p.115 - 124, 2014/12
Massive tsunami caused by the Great East Japan Earthquake attacked the Fukushima Daiichi Nuclear Power Plant and caused the nuclear accident of level 7 to overturn the safety myth of nuclear power generation. The domestic worst accident does not yet reach the convergence, and many inhabitants around the power plant are forced to double pains of earthquake disaster and nuclear accident. At present, large amounts of high-activity-level water over 500,000 tons are stored in Fukushima NPP-1 site, which is a serious obstacle to take measures for the nuclear accident. For the decontamination of high-activity-level water containing seawater, the circulating injection cooling system using packed columns with inorganic ion-exchangers is operated and the cold shutdown is accomplished. However, the advancement of operating system and the safety management of secondary solid wastes are very important subject. In this paper, the adsorption properties and solidification characteristics are compared for Cs and Sr selective adsorbents mainly composed of zeolites and the enhancement of adsorption properties are reported. Especially, naturally occurring zeolites abundant in Japan have high selectivity towards Cs, and also have excellent functions of gas trapping and self sintering for stable solidification. Zeolites are thus expected for the treatment and disposal of contaminated water in future. This paper also reports the present situation of safety management of solid wastes and the development of stable solidification methods, and summarizes the future subjects considering the safety disposal.
Konishi, Satoshi*; Enoeda, Mikio
Purazuma, Kaku Yugo Gakkai-Shi, 90(6), p.332 - 337, 2014/06
Test Blanket Module (TBM) program is to evaluate important functions of prototypical modules of DEMO breeding blankets in the real DT fusion plasma environment of ITER. Therefore, it is regarded as one of the most important milestones toward DEMO blanket. Japan is proposing a Water Cooled Ceramic Breeder (WCCB) TBM as the primary option of TBM program. Japan Atomic Energy Agency (JAEA) is performing the development of the WCCB blanket as the candidate breeding blanket of Japan, with a collaboration of universities and National Institute for Fusion Science (NIFS). Regarding the TBM development, the engineering R and Ds are ongoing, aiming at the demonstration of fabrication technology and structural integrity of the full size mockup of the WCCB TBM. Regarding the test blanket module fabrication technology development, the real scale back wall mockup was successfully fabricated. Also, the design activities are being performed to show the soundness under various loading conditions of electromagnetic force and thermo-mechanical loading. The evaluation of shutdown dose rate behind the TBM test port is also carried out as one of most important design requirement. Furthermore, key technologies toward DEMO blanket, such as, the development of advanced breeder and multiplier pebbles for DEMO blanket, fabrication technology development of Li rich LiTiO pebble and BeTi pebble was performed.
TiONakazawa, Tetsuya; Naito, Akira*; Aruga, Takeo; Grismanovs, V.*; Chimi, Yasuhiro; Iwase, Akihiro*; Jitsukawa, Shiro
Journal of Nuclear Materials, 367-370(2), p.1398 - 1403, 2007/08
Times Cited Count：43 Percentile：92.75(Materials Science, Multidisciplinary)no abstracts in English
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Sato, Masayasu; Isono, Takaaki; Sakurai, Shinji; Nakamura, Hirofumi; Sato, Satoshi; Suzuki, Satoshi; Ando, Masami; et al.
Fusion Engineering and Design, 81(8-14), p.1151 - 1158, 2006/02
Times Cited Count：124 Percentile：99.05(Nuclear Science & Technology)no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Isobe, Kanetsugu; Nishi, Masataka; Yagi, Toshiaki; Tamada, Masao
Fusion Engineering and Design, 81(1-7), p.815 - 820, 2006/02
Times Cited Count：15 Percentile：70.33(Nuclear Science & Technology)Solid-polymer-electrolyte (SPE) water electrolysis is attractive in electrolytic process of water detritiation system (WDS) in fusion reactors because it can electrolyze liquid waste directly, but radioactive durability of its ion exchange membrane is a key point. Radioactive durability of Nafion, a typical commercial ion exchange membrane, was experimentally investigated using Co-60 irradiation facility and electron beam irradiation facility at Takasaki Radiation Chemistry Research Establishment of JAERI. Nafion is composed of PTFE (Polytetrafluoroethylene) main chain. However the degradation of its mechanical strength by irradiation was significantly distinguished from that of PTFE and no serious damage was observed for its ion exchange capacity up to 530 kGy, the requirement of ITER. Atmospheric effects such as soaking and oxygen on degrading behaviors were discussed from the viewpoint of radical reaction mechanism. Dependencies of operating temperature and radioactive source are also demonstrated in detail.
Nishio, Satoshi; Omori, Junji*; Kuroda, Toshimasa*; Tobita, Kenji; Enoeda, Mikio; Tsuru, Daigo; Hirose, Takanori; Sato, Satoshi; Kawamura, Yoshinori; Nakamura, Hirofumi; et al.
Fusion Engineering and Design, 81(8-14), p.1271 - 1276, 2006/02
Times Cited Count：20 Percentile：78.69(Nuclear Science & Technology)The design guideline for the blanket is decided to meet the mission of the DEMO plant which is expected to use technologies to be proven by 2020 and present an economical prospect of fusion energy in the operational time of the reactor. To moderate the technological extrapolation, the structural material of reduced activation ferritic steel (F82H), ceramic tritium breeder of LiTiO and neutron multiplier of Be are introduced. To improve the economical aspect, the coolant material of the supercritical water with inlet/outlet temperatures of 280/510C, coolant pressure of 25 MPa is chosen. Resultantly the thermal efficiency of 41% is achieved. To obtain higher plasma performance, MHD instabilities suppressing shell structure is adopted with structural compatibility to the blanket structure. To meet higher plant availability requirement (more than 75%), the hot cell maintenance approach is selected for the replaceable power core components.
