Ma, F.; Kopecky, S.*; Alaerts, G.*; Harada, Hideo; Heyse, J.*; Kitatani, Fumito; Noguere, G.*; Paradela, C.*; alamon, L.*; Schillebeeckx, P.*; et al.
Journal of Analytical Atomic Spectrometry, 35(3), p.478 - 488, 2020/03
Okumura, Taiga*; Yamaguchi, Noriko*; Dohi, Terumi; Iijima, Kazuki; Kogure, Toshihiro*
Microscopy, 68(3), p.234 - 242, 2019/06
Radiocesium-bearing microparticles (CsMPs), consisting substantially of silicate glass, were released to the environment during the Fukushima nuclear accident in March 2011. We investigated a total of nine CsMPs using transmission electron microscopy (TEM) and inferred the atmosphere in the reactors during the accident. From elemental mapping using energy-dispersive X-ray spectrometry, Fe and Zn showing radial inhomogeneities were found in the CsMPs, in addition to the Cs that had been previously reported. Four of the CsMPs included submicron crystals, which were identified as chromite, franklinite, acanthite, molybdenite, and hessite. The chromium-containing spinels, chromite and franklinite, indicated the presence of ferrous iron (Fe), suggesting that the inside of the reactors was reductive to some extent. Electron energy-loss spectroscopy also confirmed that the CsMPs did not contain boron, and therefore the atmosphere in which they were formed might be boron-free.
Ito, Chikara; Naito, Hiroyuki; Ishikawa, Takashi; Ito, Keisuke; Wakaida, Ikuo
JPS Conference Proceedings (Internet), 24, p.011038_1 - 011038_6, 2019/01
A high-radiation resistant optical fiber has been developed in order to investigate the interiors of the reactor pressure vessels and the primary containment vessels at the Fukushima Daiichi Nuclear Power Station. The tentative dose rate in the reactor pressure vessels is assumed to be up to 1 kGy/h. We developed a radiation resistant optical fiber consisting of a 1000 ppm hydroxyl doped pure silica core and 4 % fluorine doped pure silica cladding. We attempted to apply the optical fiber to remote imaging technique by means of fiberscope. The number of core image fibers was increased from 2000 to 22000 for practical use. The transmissive rate of infrared images was not affected after irradiation of 1 MGy. No change in the spatial resolution of the view scope by means of image fiber was noted between pre- and post-irradiation. We confirmed the applicability of the probing system, which consists of a view scope using radiation-resistant optical fibers.
Okuchi, Takuo*; Tomioka, Naotaka*; Purevjav, N.*; Shibata, Kaoru
Journal of Applied Crystallography, 51, p.1564 - 1570, 2018/12
It is demonstrated that quasielastic neutron scattering (QENS) is a novel and effective method to analyse atomic scale hydrogen transport processes occurring within a mineral crystal lattice. The method was previously characterized as sensitive for analysing the transport frequency and distance of highly diffusive hydrogen atoms or water molecules in condensed matter. Here are shown the results of its application to analyse the transport of much slower hydrogen atoms which are bonded into a crystal lattice as hydroxyls. Two types of hydrogen transport process were observed in brucite, Mg(OH) : a jump within a single two-dimensional layer of the hydrogen lattice and a jump into the next nearest layer of it. These transport processes observed within the prototypical structure of brucite have direct implications for hydrogen transport phenomena occurring within various types of oxides and minerals having layered structures.
Kitatani, Fumito; Tsuchiya, Harufumi; Toh, Yosuke; Hori, Junichi*; Sano, Tadafumi*; Takahashi, Yoshiyuki*; Nakajima, Ken*
KURRI Progress Report 2017, P. 99, 2018/08
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji
Nuclear Materials and Energy (Internet), 16, p.230 - 237, 2018/08
Tsuchiya, Harufumi; Kitatani, Fumito; Toh, Yosuke; Paradela, C.*; Heyse, J.*; Kopecky, S.*; Schillebeeckx, P.*
Proceedings of INMM 59th Annual Meeting (Internet), 6 Pages, 2018/07
Teshigawara, Makoto; Ikeda, Yujiro; Oi, Motoki; Harada, Masahide; Takada, Hiroshi; Kakishiro, Masanori*; Noguchi, Gaku*; Shimada, Tsubasa*; Seita, Kyoichi*; Murashima, Daisuke*; et al.
Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01
We developed an Au-In-Cd (AuIC) decoupler material to reduce induced radioactivity instead of Ag-In-Cd one, which has a cut off energy of 1eV. In order to implement it into an actual moderator-reflector assembly, a number of critical engineering issues need to be resolved with regard to large-sized bonding between AuIC and A5083 alloys by the hot isostatic pressing process. We investigated this process in terms of the surface conditions, sizes, and heat capacities of large AuIC alloys. We also show a successful implementation of an AuIC decoupler into a reflector assembly, resulting in a remarkable reduction of radioactivity by AuIC compared to AIC without sacrificing neutronic performance.
Kitatani, Fumito; Tsuchiya, Harufumi; Koizumi, Mitsuo; Takamine, Jun; Hori, Junichi*; Sano, Tadafumi*
EPJ Web of Conferences, 146, p.09032_1 - 09032_3, 2017/09
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Uwaba, Tomoyuki; Kaito, Takeji; Onuma, Masato*
Nuclear Materials and Energy (Internet), 9, p.346 - 352, 2016/12
Oba, Yojiro*; Morooka, Satoshi; Sato, Hirotaka*; Sato, Nobuhiro*; Inoue, Rintaro*; Sugiyama, Masaaki*
Hamon, 26(4), p.170 - 173, 2016/11
Oba, Yojiro*; Morooka, Satoshi; Oishi, Kazuki*; Sato, Nobuhiro*; Inoue, Rintaro*; Adachi, Nozomu*; Suzuki, Junichi*; Tsuchiyama, Toshihiro*; Gilbert, E. P.*; Sugiyama, Masaaki*
Journal of Applied Crystallography, 49(5), p.1659 - 1664, 2016/10
Koizumi, Mitsuo; Harada, Hideo; Schillebeeckx, P.*
Nippon Genshiryoku Gakkai-Shi, 58(9), p.563 - 567, 2016/09
no abstracts in English
Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*
Journal of Nuclear Science and Technology, 52(6), p.837 - 843, 2015/06
Seya, Michio; Kobayashi, Naoki; Naoi, Yosuke; Hajima, Ryoichi; Soyama, Kazuhiko; Kureta, Masatoshi; Nakamura, Hironobu; Harada, Hideo
Book of Abstracts, Presentations and Papers of Symposium on International Safeguards; Linking Strategy, Implementation and People (Internet), 8 Pages, 2015/03
JAEA-ISCN has been implementing basic development programs of the advanced NDA technologies for nuclear material (NM) since 2011JFY (Japanese Fiscal Year), which are (1) NRF (Nuclear resonance fluorescence) NDA technology using laser Compton scattered (LCS) -rays (intense mono-energetic -rays), (2) Alternative to He neutron detection technology using ZnS/BO ceramic scintillator, and (3) NRD (Neutron resonance densitometry) using NRTA (Neutron resonance transmission analysis) and NRCA (Neutron resonance capture analysis). These programs are going to be finished in 2014JFY and have demonstration tests in February - March 2015.
Watanabe, Kazuhiro; Kashiwagi, Mieko; Kawashima, Shuichi*; Ono, Yoichi*; Yamashita, Yasuo*; Yamazaki, Choji*; Hanada, Masaya; Inoue, Takashi; Taniguchi, Masaki; Okumura, Yoshikazu; et al.
Nuclear Fusion, 46(6), p.S332 - S339, 2006/06
no abstracts in English
Nishitani, Takeo; Sugie, Tatsuo; Morishita, Norio; Yokoo, Noriko*
Fusion Engineering and Design, 74(1-4), p.871 - 874, 2005/11
no abstracts in English
Miyamoto, Yukihiro; Sakamaki, Tsuyoshi*; Maekawa, Osamu*; Nakashima, Hiroshi
JAERI-Tech 2004-054, 72 Pages, 2004/08
A standard is provided for the radiation monitor based on LAN (Local Area Network) and PLC (Programmable Logic Controller) technology at the introduction to the Japan Proton Accelerator Research Complex (J-PARC). The monitor consists of radiation measurement equipments and the central monitoring panel. The formers are installed in the radiation field, and the latter is installed in the control room and composed of PLC, which are connected with LAN. Extension of the existing standard and the conformity to the international standard were thought as important in providing the standard. The standard is expected to improve the compatibility, maintenancability and productivity of the components.
Shiroya, Seiji*; Misawa, Tsuyoshi*; Unesaki, Hironobu*; Ichihara, Chihiro*; Kobayashi, Keiji*; Nakamura, Hiroshi*; Shin, Kazuo*; Imanishi, Nobutsugu*; Kanazawa, Satoshi*; Mori, Takamasa
JAERI-Tech 2004-025, 93 Pages, 2004/03
In view of the future plan of Research Reactor Institute, Kyoto University, the present study consisted of (1) the transmission experiments of high energy neutrons through materials, (2) experimental simulation of ADSR using the Kyoto University Critical Assembly(KUCA), and (3) conceptual neutronics design study on KUR type ADSR using the MCNP-X code. Through the present study, valuable knowledge on the basic nuclear characteristics of ADSR, which is indispensable to promote the study on ADSR, was obtained both theoretically and experimentally. For the realization of ADSR, it is considered to be necessary to accumulate results of research steadily. For this purpose, it is inevitable (1) to compile the more precise nuclear data for the wide energy range, (2) to establish experimental techniques for reactor physics study on ADSR including subcriticality measurement and absolute neutron flux measurement, and (3) to develop neutronics calculation tools which take into account the neutron generation process by the spallation reaction and the delayed neutron behavior.
Morioka, Atsuhiko; Sato, Satoshi; Ochiai, Kentaro; Sakasai, Akira; Hori, Junichi; Yamauchi, Michinori*; Nishitani, Takeo; Kaminaga, Atsushi; Masaki, Kei; Sakurai, Shinji; et al.
Journal of Nuclear Science and Technology, 41(Suppl.4), p.109 - 112, 2004/03
Neutron shielding material of the port section of JT-60 superconducting modification (JT-60SC) serves as a design which used resin (KRAFTON-HB4) excellent in the temperature characteristic from polyethylene. In order to make port weight mitigate and reduce the nuclear heating of the superconducting coil, we were developed the resin which added natural BORON to resin. The 2.45MeV neutron generated in the D-D reaction was irradiated, the penetration of the neutron was measured in some kinds of samples which changed the amount of BORON, and the shielding performance of the resin containing BORON was compared with them. The penetration rates of fast neutron flux do not depend on the doped density of boron in both measurements. Whereas the penetration rates of thermal neutron flux in the resin with 2 wt% B are about 25% lower than those with 1 wt% at the back surface of the test specimens.