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Mitsuboshi, Natsumi; Nagatani, Taketeru; Kosuge, Yoshihiro*; Suzuki, Risa; Okada, Toyofumi
Dai-44-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2023/11
This paper reports the applicability confirmation experiment of DDSI method for quantification of plutonium in fuel debris. We conducted passive neutron measurement for the samples which consist of un-irradiated MOX sample, Cf-252 neutron source, and B-10 neutron absorber to simulate the fuel debris. It was revealed that DDSI method has enough capability to evaluate the leakage multiplication of the sample with unknown amounts of fissile material and neutron absorbers.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：60 Percentile：95.95(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
melt by two-dimensional detector at 1 kHzKumar, M. V.*; Kuribayashi, Kazuhiko*; Nagashio, Kosuke*; Ishikawa, Takehiko*; Okada, Jumpei*; Yu, J.*; Yoda, Shinichi*; Katayama, Yoshinori
Applied Physics Letters, 100(19), p.191905_1 - 191905_4, 2012/05
Times Cited Count：3 Percentile：12.82(Physics, Applied)
identification of metastable phases formed from the undercooled LuFeO melt under controlled oxygen partial pressure 
o
was studied by X-ray diffraction measurements at a synchrotron radiation source. Real-time observation of the formation and growth of individual phases during the single recalescence of LuFeO
and LuFeO
phases at o of 1
10
Pa has been revealed by a high speed imaging system at 1 kHz. The obtained diffraction pattern of the metastable phase in the LuFeO system was consistent with that of the metastable and stable phases reported in the Lu-Fe-O system.
Takemura, Tomoyuki*; Shingu, Kazuki*; Takahashi, Eiichiro*; Okada, Yoichi*; Takebe, Akimitsu*; Nakajima, Toshihide*; Inoue, Toshio*
JNC TJ7420 2005-033, 128 Pages, 1998/03
JNC-TJ7420-2005-033.pdf:51.98MB
The active fault survey tunnel that crossed the Mozumi-Sukenobu fault (a member of the Atotsugawa fault system) is located at the Kamioka mine, northern Gifu prefecture, Central Japan. The comprehensive study of the active fault is done by using this tunnel. The purpose of this investigation is to define the hydrological characteristics of the Mozumi-Sukenobu fault crush zones. The permeability of the crush zones is measured by the Lugeon test and the simple injection test.
Obara, Kenjiro; Kakudate, Satoshi; ; ; ; ; Adachi, Junichi*
Purazuma, Kaku Yugo Gakkai-Shi, 73(1), p.42 - 53, 1997/01
no abstracts in English
Mitsuboshi, Natsumi; Nagatani, Taketeru; Kosuge, Yoshihiro*; Okada, Toyofumi
no journal, ,
This report describes the results of applicability evaluation of the passive neutron technique for determination of the properties of fuel debris or classification of fuel debris and waste of Fukushima Daiichi Nuclear Power Plant site. The experiment and simulation revealed the effect of neutron absorber and moderator on neutron counts. The applicability of Pu mass evaluation based on the difference of half-life of Cm-244 and Pu nuclides was also evaluated by the experiment and simulation.
Broughton, D.*; Suzuki, Risa; Nagatani, Taketeru; Okada, Toyofumi; Henzlova, D.*; Longo, J.*; Mendez, J.*; Rael, C.*; Swinhoe, M. T.*
no journal, ,
This presentation will discuss issues and potential improvements in the measurement of nuclear material generated from ongoing decommissioning activities at JAEA facilities. This material is subject to safeguards requirements, but its high impurity content makes it difficult to measure using standard deployed NDA systems.
Mitsuboshi, Natsumi; Nagatani, Taketeru; Kosuge, Yoshihiro*; Okada, Toyofumi
no journal, ,
This report describes the results of applicability evaluation of the passive neutron technique for determination of the properties of fuel debris or classification of fuel debris and waste of Fukushima Daiichi Nuclear Power Plant site. The applicability of DDSI (Differential Die-Away Self-Interrogation) technique was evaluated to correct the influence of neutron absorber and moderator on neutron counts by the experiment and simulation. For Pu mass evaluation, the applicability of the methodology based on the difference of half-life of Cm-244 and Pu nuclides was also evaluated by the experiment and simulation.
Yomogida, Takumi; Yamada, Shinya*; Ichinohe, Yuto*; Sato, Toshiki*; Hayakawa, Ryota*; Okada, Shinji*; Toyama, Yuichi*; Hashimoto, Tadashi; Noda, Hirofumi*; Isobe, Tadaaki*; et al.
no journal, ,
The reduction of uranium on biotite was studied to obtain insight into the immobilization of uranium in the environment. The chemical species of uranium in biotite were studied using a superconducting transition edge sensor and an X-ray emission spectrometer to remove interference from rubidium in biotite. As a result, the speciation of uranium in biotite collected from former uranium deposits was possible. The XANES spectra of the biotite indicated that the uranium in the biotite was partially reduced.
Kubo, Jun*; Kubota, Yumi*; Okada, Akinori*; Kureta, Masatoshi; Iikura, Hiroshi; Suzuki, Hiroshi; Saito, Toru*
no journal, ,
Development of a fuel-efficient car is indispensable for the growth of the sustainable mobility society. We have carried out the visualization of the lubricating oil in a car engine and the measurement of the residual stress using neutron beam in order to reduce the friction and weight. We succeeded the high-speed visualization of the lubrication oil in the high-speed running engines by the high-frame-rate neutron radiography technique. We also measured the residual stress in the cylinder head at every material and made a database.
Pd(111) surface using supersonic ethylene molecular beamAndo, Masaaki*; Murase, Natsumi*; Tsuda, Yasutaka; Yamada, Takashi*; Yoshigoe, Akitaka; Okada, Michio*
no journal, ,
no abstracts in English
Pd(111) surface using supersonic ethylene molecular beamAndo, Masaaki*; Murase, Natsumi*; Tsuda, Yasutaka; Yamada, Takashi*; Yoshigoe, Akitaka; Okada, Michio*
no journal, ,
no abstracts in English
