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Kitamura, Akihiro; Hirano, Hiroshi*; Yoshida, Masato; Takeuchi, Kentaro
Hoken Butsuri (Internet), 58(2), p.76 - 90, 2023/08
The alpha contaminated gloveboxes have been dismantled for over 20 years in Plutonium Fuel Fabrication Facility. The so called wet recovery equipment gloveboxes, which recover plutonium and uranium from scrap fuel by dissolving and extracting processes, were chosen as the priority gloveboxes to be dismantled. These gloveboxes and other gloveboxes in the same room were size reduced and removed up until 2022. Also, non-radioactive ancillary facility and non-radioactive giant glovebox were removed from 2007 to 2010 for ease of glovebox dismantling activities that follows and for making waste storage spaces. Several incidents were occurred and recidivism prevention measures were implemented on each occasion. In this report, glovebox dismantling activities we conducted in the past 20 years are reviewed and lessons we have learned are summarized.
OKondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count：6 Percentile：93.26(Multidisciplinary Sciences)no abstracts in English
Ne at the transition into the island of inversion; Detailed structure study of NeWang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
Times Cited Count：2 Percentile：83.53(Astronomy & Astrophysics)Detailed 
-ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Iwasaki, Yuma*; Sawada, Ryoto*; Stanev, V.*; Ishida, Masahiko*; Kirihara, Akihiro*; Omori, Yasutomo*; Someya, Hiroko*; Takeuchi, Ichiro*; Saito, Eiji; Yorozu, Shinichi*
npj Computational Materials (Internet), 5, p.103_1 - 103_6, 2019/10
Times Cited Count：47 Percentile：87.54(Chemistry, Physical)Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：8 Percentile：55.71(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Iwasaki, Yuma*; Takeuchi, Ichiro*; Stanev, V.*; Gilad Kusne, A.*; Ishida, Masahiko*; Kirihara, Akihiro*; Ihara, Kazuki*; Sawada, Ryoto*; Terashima, Koichi*; Someya, Hiroko*; et al.
Scientific Reports (Internet), 9, p.2751_1 - 2751_7, 2019/02
Times Cited Count：61 Percentile：93.15(Multidisciplinary Sciences)Kono, Takahiko; Tanaka, Masato*; Sakoda, Akihiro; Tanaka, Hitomi*; Takeuchi, Masato*; Kataoka, Noriaki*
Proceedings of World Engineers Convention Australia 2019 (WEC 2019) (Internet), p.486 - 496, 2019/00
Tc solution from 
Mo to be obtained by (
) reaction; A Preliminary study using inactive Re instead of TcTanase, Masakazu*; Fujisaki, Saburo*; Ota, Akio*; Shiina, Takayuki*; Yamabayashi, Hisamichi*; Takeuchi, Nobuhiro*; Tsuchiya, Kunihiko; Kimura, Akihiro; Suzuki, Yoshitaka; Ishida, Takuya; et al.
Radioisotopes, 65(5), p.237 - 245, 2016/05
no abstracts in English
Tobita, Toru; Nakagawa, Sho*; Takeuchi, Tomoaki; Suzuki, Masahide; Ishikawa, Norito; Chimi, Yasuhiro; Saito, Yuichi; Soneda, Naoki*; Nishida, Kenji*; Ishino, Shiori*; et al.
Journal of Nuclear Materials, 452(1-3), p.241 - 247, 2014/09
Times Cited Count：17 Percentile：78.17(Materials Science, Multidisciplinary)Three kinds of Fe-based model alloys, Fe-0.018 atomic percent (at.%) Cu, Fe-0.53at.%Cu, and Fe-1.06at.%Cu were irradiated with 2 MeV electrons up to the dose of 2
10
dpa at 250
C. After the irradiation, the increase in Vickers hardness and the decrease in electrical resistivity were observed. The increase in hardness by electron irradiation is proportional to the product of the Cu contents and the square root of the electron dose. The decrease in electrical resistivity is proportional to the product of the square of Cu contents and the electron dose. Cu clustering in the materials with electron irradiation and thermal aging was observed by means of the three dimensional atom probes (3D-AP). The change in Vickers hardness and electrical resistivity is well correlated with the volume fraction of Cu clusters.
Yamaguchi, Masaaki; Maekawa, Keisuke; Takeuchi, Shinji*; Kitamura, Akihiro; Onishi, Yasuo*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 20(2), p.53 - 69, 2013/12
We developed a simple novel and fast simulation model to predict a long-term distribution of 
Cs deposited on the land surface of Fukushima due to the Fukushima Dai-ichi Nuclear Power Plant accident triggered by a magnitude 9.0 earthquake and resulting tsunami on 11 March 2011. The model utilizes the Geographical Information System (GIS) to integrate online open data provided by individual institutes, and simulate mechanisms of soil erosion, transport and sedimentation. A preliminary calculation shows the significant deposition of sediments in lakes and reservoirs and eroded silt and clay tend to be transported downstream to river mouths than eroded sand. These results were found to be qualitatively consistent with existing data.
Tc production from (n,)Mo based on solvent extractionKimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.
Proceedings of 3rd Asian Symposium on Material Testing Reactors (ASMTR 2013), p.109 - 115, 2013/11
JP, 2011-173260 
Patent publication (In Japanese)
Tc is generated by decay of Mo. Production of Mo is carried out by (n,f) method with high enriched uranium targets, and the production are currently producing to meet about 95% of global supply. Recently, it is difficult to carry out a stable supply for some problems such as aging of reactors etc. Furthermore, the production has difficulties in nuclear proliferation resistance etc. Thus, (n,) method has lately attracted considerable attention. The (n,) method has several advantages, but the extremely low specific activity makes its uses less convenient than (n,f) method. We proposed a method based on the solvent extraction, followed by adsorption of Tc with alumina column. In this paper, a practical production of Tc was tried by the method with 1Ci of Mo produced in MPR-30. The recovery yields were approximately 70%. Impurity of Mo was less than 4.010% and the radiochemical purity was over 99.2%.
Kimura, Nobuaki; Takeuchi, Tomoaki; Shibata, Akira; Takemoto, Noriyuki; Kimura, Akihiro; Naka, Michihiro; Nishikata, Kaori; Tanimoto, Masataka; Tsuchiya, Kunihiko; Sano, Tadafumi*; et al.
KURRI Progress Report 2012, P. 209, 2013/10
In research reactors, CCD cameras are used to observe reactor core for reactor operation management, e.g. to prevent debris from falling. In order to measure the reactor power and fuel burnup exactly by means of observation of Cherenkov light, the development of the on-line measurement device started in 2009. In this study, the wavelength and the absolute irradiance of the Cherenkov light were measured by a spectrometer, and the Cherenkov light was observed by the CCD camera. As a result, the measurement value is good agreement with the nominal value. On the other hand, the value by the visible imaging system was obtained the same tendency of nominal transmittance value of ND-filters.
Tc production from (n,)Mo based on solvent extraction and column chromatographyKimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.
Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 7 Pages, 2013/10
JP, 2011-173260Patent publication (In Japanese)
This research is development of Tc production. Tc is generated by decay of Mo. The supply of Mo in Japan depends entirely on the import from foreign countries. Thus, it is needed to supply Mo stably by the domestic manufacturing. A practical production of Tc was tried by the method with 1 Ci of Mo produced in MPR-30. The results showed that the recovery yields were approximately 70%. The concentration of the product obtained was estimated to be corresponding to about 30 GBq (800 mCi)/ml when 150g of MoO
was irradiated for 5 days in MPR-30. Impurity of Mo was less than 4.410%, which was lower than that of Japanese tentative regulation criteria. The radiochemical purity was higher than 99.8% that cleared the tentative regulation (95%) of Japan.
Tc production from (n, ) MoTanase, Masakazu*; Shiina, Takayuki*; Kimura, Akihiro; Nishikata, Kaori; Fujisaki, Saburo*; Ota, Akio*; Kobayashi, Masaaki*; Yamamoto, Asaki*; Kawauchi, Yukimasa*; Tsuchiya, Kunihiko; et al.
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10
Tc is used as a radiopharmaceutical and manufactured from the parent nuclide of Mo. Extraction method of Tc from (n, ) Mo have been developed, as a part of the industrial use expansion after JMTR will re-start. In this research, the method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities. The method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities.
Al cable-in-conduit conductorKoizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Nakajima, Hideo; Takeuchi, Takao*; Banno, Nobuya*; Kikuchi, Akihiro*
Teion Kogaku, 46(8), p.495 - 499, 2011/08
JAEA and NIMS has been collaborating in development of high performance Rapid-Heating-Quenching-Transformation (RHQT) NbAl CIC conductor, aiming at the application of this conductor to DEMO plant. The technical issue of the RHQT NbAl strand in the application to a fusion magnet is stabilization against perturbation. NIMS developed technique to attach copper stabilizer by using electroplating and a sub-scale CIC conductor is developed using this conductor. JAEA performed stability test of the developed CIC conductor to demonstrate efficiency of this copper stabilization technique. The measured stability margin is sufficiently high compared to the one of similar NbTi CIC conductor previously tested by the authors. Then, it can be concluded that the copper stabilizer works efficiently from view point of stability, resulting in solving the remained technical issues in the RHQT CIC conductor. Therefore, we can say that the RHQT NbAl CIC conductor is the most promising candidate for application to magnet in DEMO plant.
Al strands subjected to an axial-strain for fusion DEMO reactorHemmi, Tsutomu; Koizumi, Norikiyo; Nunoya, Yoshihiko; Okui, Yoshio*; Matsui, Kunihiro; Nabara, Yoshihiro; Isono, Takaaki; Takahashi, Yoshikazu; Okuno, Kiyoshi; Banno, Nobuya*; et al.
IEEE Transactions on Applied Superconductivity, 19(3), p.1540 - 1543, 2009/06
Times Cited Count：16 Percentile：62.03(Engineering, Electrical & Electronic)NbAl cable-in-conduit (CIC) conductors have been developed as one of candidates for the fusion DEMO reactor. The performances of superconducting strands in the CIC conductor are affected by transverse electromagnetic force and thermal strain at reaction heat treatment. In order to accurately design the conductors for the fusion DEMO reactor, the performance evaluation of the NbAl strands, which is processed by a rapid heating, quenching and transformation (RHQT) method, was performed under various temperature, magnetic field and axial-strain conditions. The measured and parameterized results of the NbAl strands are presented.
Al developmentTakeuchi, Takao*; Kikuchi, Akihiro*; Banno, Nobuya*; Kitaguchi, Hitoshi*; Iijima, Yasuo*; Tagawa, Kohei*; Nakagawa, Kazuhiko*; Tsuchiya, Kiyosumi*; Mitsuda, Shiori*; Koizumi, Norikiyo; et al.
Cryogenics, 48(7-8), p.371 - 380, 2008/07
Times Cited Count：62 Percentile：87.94(Thermodynamics)NbAl has advantages of better tolerance to strain/stress and a higher critical magnetic field (30 T at 4.2 K) for stoichiometric composition over NbSn. The rapid-heating, quenching and transformation annealing (RHQT) process enables to form a stoichiometric NbAl with fine grain structures via metastable bcc supersaturated-solid-solution. As a result a large critical current density of NbAl is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized NbAl strand is about be commercially available for NMR uses. Ag or Cu internal stabilization and Cu ion-plating/electroplating techniques have been also developed to enable the stabilized round wire for accelerator and fusion magnets. Successfully energized test coils that were manufactured with a wind-and-react technique have demonstrated that a long piece of Cu stabilized RHQT NbAl wire is really available for practical applications.
Al superconductors with Ta matrixTakeuchi, Takao*; Tagawa, Kohei*; Noda, Tetsuji*; Banno, Nobuya*; Iijima, Yasuo*; Kikuchi, Akihiro*; Kitaguchi, Hitoshi*; Kosuge, Michio*; Tsuchiya, Kiyosumi*; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 16(2), p.1257 - 1260, 2006/06
Times Cited Count：6 Percentile：37.27(Engineering, Electrical & Electronic)Next generation nuclear fusion magnets would require a high-current conductor in fields more than 16 T. A CIC conductor of the rapid RHQT processed NbAl may be a promising candidate. Good deformability of intermediately-formed bcc supersaturated-solid solution indeed allowed fabricating such a CIC conductor, which would be subsequently transformation annealed. Ag has been internally included as a basic constituent of a round strand so far, because Ag is almost non-reactive with Nb matrix during the RHQ. However, both of Ag and Nb are not suitable nuclei from the viewpoint of radioactivity when irradiated with neutrons. Recently, we have succeeded in replacing the Nb matrix with Ta that has the advantage of shorter half-life of radioactivity. In the present study, an attempt has been made to replace the Ag internal stabilizer with Cu, in the aim of further reducing radioactivity, based on anticipation that Ta would be less reactive with Cu than Nb did.
Sagisaka, Akito; Azuma, Hirozumi*; Daido, Hiroyuki; Kamiya, Nobuo*; Ito, Tadashi*; Takeuchi, Akihiro*; Suzuki, Noritomo*; Nishimura, Akihiko; Mori, Michiaki; Orimo, Satoshi; et al.
Proceedings of 4th International Congress on Laser Advanced Materials Processing (LAMP 2006) (Internet), 3 Pages, 2006/00
no abstracts in English
