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Cs concentrations from the Fukushima Daiichi Nuclear Power Plant accident, phase III; Simulation with an identical source term and meteorological field at 1-km resolutionSato, Yosuke*; Sekiyama, Tsuyoshi*; Fang, S.*; Kajino, Mizuo*; Qu
rel, A.*; Qulo, D.*; Kondo, Hiroaki*; Terada, Hiroaki; Kadowaki, Masanao; Takigawa, Masayuki*; et al.
Atmospheric Environment; X (Internet), 7, p.100086_1 - 100086_12, 2020/10
The third model intercomparison project for investigating the atmospheric behavior of Cs emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident (FDNPP-MIP) was conducted. A finer horizontal grid spacing (1 km) was used than in the previous FDNPP-MIP. Nine of the models used in the previous FDNPP-MIP were also used, and all models used identical source terms and meteorological fields. Our analyses indicated that most of the observed high atmospheric Cs concentrations were well simulated, and the good performance of some models improved the performance of the multi-model ensemble. The analyses also confirmed that the use of a finer grid resolution resulted in the meteorological field near FDNPP being better reproduced. The good representation of the wind field resulted in the reasonable simulation of the narrow distribution of high deposition amount to the northwest of FDNPP and the reduction of the overestimation over the area to the south of FDNPP. In contrast, the performance of the models in simulating plumes observed over the Nakadori area, the northern part of Gunma, and the Tokyo metropolitan area was slightly worse.
system using a combination of X-ray diffraction and differential thermal analysesNakayoshi, Akira; Kitawaki, Shinichi; Fukushima, Mineo; Murakami, Tsuyoshi*; Kurata, Masaki
Journal of Nuclear Materials, 441(1-3), p.468 - 472, 2013/10
Times Cited Count：14 Percentile：72.14(Materials Science, Multidisciplinary)Electrorefining is one of the main steps of pyroreprocessing where spent nuclear fuels are recycled. Electrorefining is conducted in a molten salt of LiCl-KCl eutectic (59:41 mol%) containing actinide chlorides (AnCl) at 773 K. In order to operate and maintain the electrorefiner, it is necessary to accumulate fundamental data on LiCl-KCl-AnCl salt such as the melting point. In this study, based on X-ray diffraction and differential thermal analysis, a partial phase diagram of (LiCl-KCl)eut.-UCl pseudo-binary system and partial phase diagram of LiCl-KCl-UCl system were developed, which UCl concentration was up to 20 mol%.
Okumura, Susumu; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; Nara, Takayuki; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 172, 2013/01
The AVF cyclotron was operated from May 9th in fiscal 2011 and all the planned experiments on April were cancelled due to scheduled blackouts originated from the Great East Japan Earthquake. The total operation time amounted to 3,038.4 hours. The extended operation from Friday evening to Saturday evening was carried out eight times in order to supply the cancellation on April. The regular yearly overhaul and maintenance were carried out.
Yokota, Wataru; Sato, Takahiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Koka, Masashi; Takano, Katsuyoshi*; Yokoyama, Akihito; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 159, 2012/01
The development of the fast single-ion hit system was continued from last year in order to improve the quality of microbeam and single-ion hit at the TIARA cyclotron of the Japan Atomic Energy Agency. The major subjects were reduction of miss hit, no hit on the targeted point by any ions in the single-ion-hit irradiation, and development of a real-time detection system of single-ion hit. A new microbeam of 400 MeV-Fe with a spot diameter of about 4 
m was also developed and supplied to an experiment.
Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 172, 2012/01
no abstracts in English
Al
CKoyama, Takehide*; Ozaki, Yuzuru*; Ueda, Koichi*; Mito, Takeshi*; Kohara, Takao*; Waki, Tsuyoshi*; Tabata, Yoshikazu*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Suzuki, Michito; et al.
Physical Review B, 84(21), p.212501_1 - 212501_4, 2011/12
Times Cited Count：12 Percentile：44.66(Materials Science, Multidisciplinary)The results of 
Al nuclear magnetic resonance and specific-heat measurements of the noncentrosymmetric superconductor MoAlC are reported. The phase transition around 130 K is inferred from a distinct change in the NMR spectrum, a clear peak in the spin-echo decay rate, and an anomaly in the specific heat. Possibility of charge-density wave ordering around 130 K is discussed by calculating the Fermi surfaces in the normal states and considering the partial quenching of the Fermi surfaces with the decrease in 1/
below the superconducting transition temperature.
Kitawaki, Shinichi; Nakayoshi, Akira; Fukushima, Mineo; Sakamura, Yoshiharu*; Murakami, Tsuyoshi*; Akiyama, Naoyuki*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/09
In the FaCT project, the metal fuel cycle including metal fuel fast reactor and pyrochemical reprocessing has been being developed. JAEA and CRIEPI have continued a collaborative study on pyrochemical reprocessing. In the pyrochemical reprocessing, actinides in the spent fuels dissolve anodically in the LiCl-KCl, and U is collected selectively on a solid cathode, Pu and MA are recovered simultaneously in a liquid Cd cathode. In the previous electrorefining tests, at the anode Zr was allowed to dissolve into the electrolyte salt together with U, Pu and MA. The Zr co-dissolution may cause some problems. In this study, through the anode dissolution test of U-Pu-Zr alloy fuel, the controlling the dissolution of the Zr and the improvement of dissolution ratio of U, Pu were studied. The U-Pu alloy was prepared from MOX pellets by using the electrochemical reduction method. U-Pu-Zr ternary alloy was produced by alloying the obtained U-Pu alloy and prepared U-Zr alloy. U-Pu-Zr ternary alloy was immersed into electrolyte salt, and electrolysis test was carried out.
Murakami, Tsuyoshi*; Sakamura, Yoshiharu*; Akiyama, Naoyuki*; Kitawaki, Shinichi; Nakayoshi, Akira; Fukushima, Mineo
Journal of Nuclear Materials, 414(2), p.194 - 199, 2011/07
Times Cited Count：17 Percentile：77.43(Materials Science, Multidisciplinary)An electrorefining is one of the main steps of pyrochemical reprocessing of spent metallic fuels (U-Zr, U-Pu-Zr). The electrorefining is carried out dissolving a portion of Zr together with actinides to accomplish a high dissolution ratio of actinides. However, the electrorefining with Zr co-dissolution should bring some practical problems in the pyrochemical reprocessing. Therefore, electrorefining tests of non-irradiated U-Pu-Zr alloy were performed with minimizing the amount of Zr dissolved in LiCl-KCl-(U, Pu, Am)Cl melts at 773 K. The tests were performed both by potentiostatic electrolysis at -1.0 V (Ag
/Ag) that was more negative than the Zr dissolution potential and by galvanostatic electrolysis with a limited amount of Zr dissolution. The ICP-AES analysis of the anode residues confirmed that a high dissolution ratio of actinides (U; 
99.6%, Pu; 99.9%) was successfully demonstrated at both electrolyses.
Yokota, Wataru; Sato, Takahiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Koka, Masashi; Takano, Katsuyoshi; Kamiya, Tomihiro
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 173, 2011/01
Microbeam and single-ion hit of 260 MeV-
Ne
and/or 520 MeV-
Ar
were utilized to irradiate living biological cells for study of radiation biology, semiconductor devices for study of radiation effects such as Single Event Upset and polymer films for study of micro-fabrication in fiscal 2009 at the TIARA cyclotron. Although these beams were generally supplied smoothly, we still have technical matters to improve for better beam quality. One of the major subjects is instability of microbeam, and another is miss hit, no ion hit around a targeted point. The paper describes investigation of the causes of those as well as development of new ion beams to be available for microbeam and single-ion hit.
Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; et al.
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 180, 2011/01
no abstracts in English
Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 190, 2008/11
no abstracts in English
Kitawaki, Shinichi; Shinozaki, Tadahiro; Fukushima, Mineo; Usami, Tsuyoshi*; Yahagi, Noboru*; Kurata, Masaki*
Nuclear Technology, 162(2), p.118 - 123, 2008/05
Times Cited Count：18 Percentile：74.54(Nuclear Science & Technology)A series test of pyro-process was carried out to recover U-Pu alloy from MONJU MOX pellets. In the Li-reduction step, the reduction behavior of MOX was similar to that of UO
. In the electrorefining step, the separation factor between U and Pu was 5.7 for the combination of reduced MOX anode and liquid cadmium cathode, which is almost comparable to the value in the previous studies. For the material balance, approximately 98% of U and 103% of Pu were detected in the electrodes or molten salt after the electrolysis with respect to the initial amounts in the anode or molten salt. Considering the analytical error of ICP-AES, these values are reasonable. The remained amount of U in the anode was slightly larger than that of Pu due to the re-oxidation. The U-Pu alloy ingot was successfully formed by distillation of Cd.
Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 204, 2008/03
no abstracts in English
Yuyama, Takahiro; Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.259 - 261, 2008/00
no abstracts in English
Koyama, Tadafumi*; Hijikata, Takatoshi*; Usami, Tsuyoshi*; Inoue, Tadashi*; Kitawaki, Shinichi; Shinozaki, Tadahiro; Fukushima, Mineo; Myochin, Munetaka
Journal of Nuclear Science and Technology, 44(3), p.382 - 392, 2007/03
Times Cited Count：24 Percentile：82.59(Nuclear Science & Technology)Electrometallurgical pyroprocessing is a promising technology to realize actinide fuel cycle. Integrated experiments to demonstrate electrometallurgical pyroprocessing of plutonium oxide in continuous operation were carried out. In each test, 10 to 20 g of PuO was reacted with Li reductant to form metal product. The reduction products were charged in the anode basket of the electrorefiner with LiCl-KCl-UCl electrolyte. With using the anodes, deposition of uranium on the solid cathode was carried out, when PuCl concentration was low. After Pu/U ratio in salt electrolyte was increased enough, plutonium and uranium were recovered simultaneously on the liquid cadmium cathode. By heating up the deposits for distillation of the salt and the cadmium, U metal or Pu-U alloyed metal were obtained as residues in the crucible. It was first result to demonstrate the recovery of metal actinides in the continuous operation of pyroprocessing of oxide fuels.
Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; Yokota, Wataru; et al.
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 196, 2007/02
no abstracts in English
Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Fukuda, Mitsuhiro; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Nakamura, Yoshiteru; et al.
JAEA-Review 2005-001, TIARA Annual Report 2004, P. 370, 2006/01
no abstracts in English
Kitawaki, Shininchi; Shinozaki, Tadahiro; Fukushima, Mineo; Hijikata, Takatoshi*; Usami, Tsuyoshi*; Koyama, Tadafumi*
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10
Electrometallurgical pyroprocess is a key innovative technology to realize closed actinides cycle with keeping high proliferation-resistance and economy. JNC and CRIEPI have been carrying out the integrated tests of electrometallurgical reprocessing of metal and oxide Pu-containing fuel to demonstrate whole process in continuous operation. After intensive cold test to confirm the functions of experimental apparatus and the test conditions, recovery test of actinide metal product from actinide oxide fuels has started as a first series of the integrated tests. In this report, result of the recovery test is described to elucidate the material flow in the process.
Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Fukuda, Mitsuhiro; Okumura, Susumu; Miyawaki, Nobumasa; Nakamura, Yoshiteru; Akaiwa, Katsuhiro*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.209 - 211, 2004/08
no abstracts in English
TiO added with TiOHoshino, Tsuyoshi; Kobayashi, Takeshi*; Nashimoto, Makoto*; Kawamura, Hiroshi; Dokiya, Masayuki*; Terai, Takayuki*; Yamawaki, Michio*; Takahashi, Yoichi*
JAERI-Conf 2004-012, p.140 - 147, 2004/07
no abstracts in English
