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Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Kogure, Toshihiro*; Okochi, Takuo*; Yasui, Akira*; et al.
Applied Physics Letters, 112(2), p.021603_1 - 021603_5, 2018/01
Times Cited Count:8 Percentile:34.98(Physics, Applied)A synchrotron radiation photoemission electron microscope (SR-PEEM) was applied to demonstrate pinpoint analysis of micrometer-sized weathered biotite clay particles with artificially adsorbed cesium (Cs) atoms. Despite the insulating properties of the clay, we observed the spatial distributions of constituent elements (Si, Al, Cs, Mg, Fe) without charging issues. We found that Cs atoms were likely to be adsorbed evenly over the entire particle. Spatially-resolved X-ray absorption spectra (XAS) of the Cs M-edge region showed Cs to be present in a monocation state (Cs). Further pinpoint XAS measurements were also performed at the Fe L-edge to determine the chemical valence of the Fe atoms. Our results demonstrate the utility of SR-PEEM as a tool for spatially-resolved chemical analyses of various environmental substances, which is not limited by the poor conductivity of samples.
Mita, Yutaka; Matsumura, Toshihiro; Yokoyama, Kaoru; Sugitsue, Noritake
JAEA-Technology 2008-061, 35 Pages, 2008/10
In Ningyo-toge Environmental Engineering Center. The equipments and radioactive waste which were contaminated with uranium are generated so much in future dismantling stage. In our plan, some of equipments and radioactive waste are decontamination to a clearance level, and cut down on decommission and disposal expense. This plan needs the alpha-rays measurement technology of the very low level. We think that ionized Air transfer measurement technology is promising as of clearance verification technology. The ionized Air transfer measurement technology applied to the Ionized Air Type Measurement can measure alpha radioactivity of a very low level. Moreover, as compared with a direct survey, there is the merit which can be measured in a short time. However ionized Air transfer measurement technology is new technology. Therefore, there is almost no measurement track record. Furthermore, the date about the influence of a background, a detection limit, measurement performance, and reliability is insufficient. So, this measurement test estimated applicability as clearance level verification of an Ionized Air Type Measurement.
Koga, Osamu; Nagara, Shuichi; Matsumura, Toshihiro; Takeuchi, Akira*; Takeda, Shinji; Yamamoto, Masahiro*; Sato, Kazuhiko
JNC TN6440 2004-003, 66 Pages, 2004/03
To analyze high precision in groundwater flow and radionuclide transport around Yotsugi open-pit mining place site and around Yotsugi mill tailing yard, besides the topic in past analysis is extracted, following it did examination of the corresponding method and arrangement of physical properties value.
Nagara, Shuichi; Yamamoto, Masahiro*; Koga, Osamu; Takeuchi, Akira; Matsumura, Toshihiro; Takeda, Shinji; Sato, Kazuhiko
JNC TN6420 2004-001, 75 Pages, 2004/03
The radon concentration in groundwater summarized around the Yotsugi open-pit site has been measured from 2002 to 2003 and examined radon observation system built in 2001. Moreover, the maintenance actual result of the radon observation system was summarized.
Matsumura, Toshihiro; Sato, Kazuhiko; Tokizawa, Takayuki
Saikuru Kiko Giho, (16), p.51 - 62, 2002/09
None
Nagara, Shuichi; Matsumura, Toshihiro; Sato, Kazuhiko; Tokizawa, Takayuki
JNC TN6400 2004-005, 34 Pages, 2002/03
A one-dimensional numerical solute-transport analysis utilizing a simulation code named NESTOR, involving a literature survey on analytical parameters has been carried out for the purpose of an understanding radionuclide transport in groundwater in and around the former Yotsugi open pit site at the Ningyo-Toge Environmental Engineering Center, JNC. Prior to the analysis, data set was prepared referring to available documents on site characteristics and one on disposal of radwaste. A simplified model in which the site was divided into seven blocks according to its geographical-hydrological feature and has boreholes downward regarded as assessment points was applied on the analysis. As a result, The highest concentrations of radionuclide is 8.5710 Bq/m of Po-210 at assessment points. The highest concentration of U-238 is in the order of magnitude of 10 Bq/m. This figure is lower by 1 order than a standard value for mine- and waste-water on the safety rule of Ningyo-Toge mine and the same orders as surface-water on the agreement with Okayama prefecture. If the analysis result in this time and the present concentration in groundwater are measured, the former data became lower about 7 orders by U-238 concentrations and became lower about 6 orders by Ra-226 concentrations. It is thought that this cause is that U and Ra which exist around the former Yotsugi open pit sit before taking reclamation cannot be taking into consideration in analysis.
Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Tamura, Hiroyuki; Kurashima, Satoshi; Yokota, Wataru; Okumura, Susumu; Fukuda, Mitsuhiro; Akaiwa, Katsuhiro*; et al.
Proceedings of 13th Symposium on Accelerator Science and Technology, p.193 - 195, 2001/00
The AVF cyclotron system at JAERI Takasaki has been smoothly operated without serious troubles since the first beam extraction in March, 1991. A yearly operation time is about 3200 hours on an average for recent eight years. In last two years, we performed some improvements and developments as followings: stabilization of the cyclotron beam by addition on an exclusive cooling system, designing and investigation of the flat-top system using fifth-harmonic RF, reconstruction of the rotary shutter for radiation shielding and reinforcement of the magnetic channel and its power supply. Furthermore, the renewal of main circulation pump for cooling system, replacement of shunt resistor in the power supplies and re-alignment of the several magnets along the trunk beam transport line were also carried out.
Tokizawa, Takayuki; Matsumura, Toshihiro; Yabuta, Naohiro*; Kawai, Jun*; Hikawa, Tamae*
no journal, ,
An ethnographical research was conducted by the regional high school students for the Ningyo-Toge uranium production facilities. The research was focused on several social groups around Ningyo-Toge such as engineers in the facilities and residents and described past and present circumstances there from the time firstly discovered an uranium ore 50 years ago. In addition, it should be noted that regional communication around Ningyo-Toge were activated while the research project was conducted.
Mita, Yutaka; Matsumura, Toshihiro; Sugitsue, Noritake; Yamaguchi, Hiromi; Sano, Akira*; Naito, Susumu*; Maekawa, Tatsuyuki*; Yoshimura, Yukio*; Matsumoto, Takashi*
no journal, ,
By using Ionized Air Type Measurement Apparatus which was designed to measure clearance level of dismantled large-scale things which generate from nuclear plants, after chemical decontaminating machinery and materials which are used in plants, we experimented on a real-scale measurement of clearance level of them. We evaluated performance of detection and confirm applicability as a system of measurement of clearance level.
Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Yaita, Tsuyoshi; Kogure, Toshihiro*; Motai, Satoko*; et al.
no journal, ,
Fundamental researches on adsorption state of radiaoactive Cs in clay mineral (aluminosilicate) have become important from the virewpoints of development of decontamination or volume-reduction techniques since the accident of Fukushima Daiiichi Nuclear Power Station. Pinpoint surface chemical analysis with nanometer spatial resolutions focusing on a target sample has been needed. In this presentation, I will show our recent work on nanoscale pinpoint surface chemical analysis for Cs-containing clay mineral by means of synchrotron radiation PEEM at BL17SU in SPring-8.
Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Yaita, Tsuyoshi; Kogure, Toshihiro*; Motai, Satoko*; et al.
no journal, ,
Pinpoint chemical analysis for Cs-adsorbed vermiculite was performed by using synchrotron radiation photoelectron emission microscopy (SR-PEEM). It was found that Cs is distributed through the micro-size clay particles and we also succeeded to measure pinpoint X-ray absorption spectra for constituent element simultaneously. Furthermore, we precisely confirmed the existence of Fe in the sample.
Nohara, Tsuyoshi; Takesue, Norito; Matsumura, Toshihiro*; Nakagiri, Toshio; Takeuchi, Shinji*
no journal, ,
It was reported that traces of high and low permeable zones formed by the supercritical fluid flow through granite have been observed in Japan. These traces directly related to current permeability. In this study, we will improve the investigation methods and evaluation technologies considering the influence of supercritical fluids through case studies in the Ningyo-toge area. In this presentation, we will introduce the research plan and the preliminary results.