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SUGIYAMA Wataru

    Atomic Energy Research Institute　Associate Professor
Last Updated :2024/04/25

Researcher Information

URL

J-Global ID

Research Areas

  • Energy / Nuclear engineering

Academic & Professional Experience

  • 2015/04 - Today  Kindai UniversityAtomic Energy Research Institute准教授
  • 2011 - Today  Kindai UniversityAtomic Energy Research Institute原子炉主任技術者
  • 2008/04 - 2015/03  Kindai University講師
  • 1995/04 - 2008/03  中部電力株式会社

Education

  • 2002/04 - 2005/03  Shinshu University  工学系研究科  材料工学専攻（社会人博士課程）

Association Memberships

  • 日本イオン交換学会   日本原子力学会   

Published Papers

  • Ryohei Okuda; Atsushi Sakon; Sin-ya Hohara; Wataru Sugiyama; Hiroshi Taninaka; Kengo Hashimoto
    JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY TAYLOR & FRANCIS LTD 53 (10) 1647 - 1652 0022-3131 2016 [Refereed]
     
    The bunching technique has been widely utilized in Feynman- neutron correlation analysis to synthesize neutron counts within longer gate widths by bunching time-sequence neutron counts stored in multichannel scaler channels. An alternative technique referred to as moving-bunching technique was proposed to reduce a statistical scatter of variance-to-mean ratio of neutron counts. The conventional bunching technique has no overlap of adjacent bunches, while the present technique makes adjacent bunches overlap as long as possible similarly to the moving average technique. A Feynman- experiment was performed in the UTR-KINKI, to confirm the advantage of the proposed bunching technique. When a neutron detector was placed far from the core, a Feynman- analysis with the conventional bunching technique led to a scattered variance-to-mean ratio from which the prompt-neutron decay constant was never determinable. However, another analysis with the proposed technique remarkably reduced the above scatter and enabled the determination of the decay constant. For a neutron detector close to the core, the proposed technique also reduced statistical error of the decay constant.
  • Atsushi Sakon; Kengo Hashimoto; Wataru Sugiyama; Sin Ya Hohara; Cheol Ho Pyeon; Tadafumi Sano; Takahiro Yagi; Takaaki Ohsawa
    Journal of Nuclear Science and Technology 52 (2) 204 - 213 0022-3131 2015/02 
    © 2014 Atomic Energy Society of Japan. All rights reserved. A unique power spectral analysis for a subcritical reactor system driven by a pulsed 14 MeV neutron source was carried out at the Kyoto University Critical Assembly (KUCA). In this analysis, a complex cross-power spectral density between time-sequence signal data from an accelerator beam ammeter and a neutron detector was measured to determine the prompt-neutron decay constant of an accelerator-driven system (ADS) from the phase data of the spectral density. Assuming the one-point kinetics model, in theory, the decay constant can be arithmetically derived from the phase at the integral multiples of the pulse repetition frequency. However, the actual derivation from the phase at a pulse repetition frequency of 20 Hz considerably underestimated the prompt-neutron decay constant, compared with that obtained by a previous pulsed neutron experiment, and the derived decay constant apparently decreased with an increase in the multiple of the pulsed repetition frequency. Considering a lag time in detector response, the above underestimation and the above apparent decrease were solved to obtain the consistent decay constant. While both previous power spectral analysis and Feynman-α analysis for pulsed neutron source require non-linear least-squares fits of the respective complicated formulae, the present analysis makes the fitting unnecessary except at regular calibration of the lag time. This feature is advantageous for a robust online monitoring of subcritical reactivity of an actual ADS.
  • Sin-ya Hohara; Masayo Inagaki; Hirokuni Yamanishi; Genichiro Wakabayashi; Wataru Sugiyama; Tetsuo Itoh
    The 12th International Conference on Radiation Shielding (ICRS-12) and the 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS (RPSD-2012), Progress in Nuclear Science and Technology 4 39 - 42 2014/04 [Refereed]
  • Atsushi Sakon; Kengo Hashimoto; Muhamad Aiman Bin Maarof; Masahiro Kawasaki; Wataru Sugiyama; Cheol Ho Pyeon; Tadafumi Sano; Takahiro Yagi; Takaaki Ohsawa
    Journal of Nuclear Science and Technology 51 (1) 116 - 126 0022-3131 2014/01 
    Large negative reactivity of a subcritical system driven by a pulsed 14 MeV neutron source has been measured in the Kyoto University Critical Assembly. The subcriticality of the accelerator-driven system (ADS) ranged in effective multiplication factor roughly from 0.98 to 0.92, which corresponded to an operational range of an actual ADS proposed by Japan Atomic Energy Agency. As the measurement technique, pulsed neutron method, power spectral analysis for pulsed neutron source, accelerator-beam trip method were employed. From neutron count decay data obtained by the pulsed neutron experiment, not only the prompt-neutron decay constant of fundamental mode but also a higher spatial mode could be derived. The subcriticality was also determined from the fundamental decay constant. The measured cross-power spectral density consisted of a familiar correlated reactor-noise component and many uncorrelated delta-function-like peaks at the integral multiple of pulse repetition frequency. The fundamental prompt-neutron decay constant, i.e., the subcriticality determined from the latter uncorrelated peaks was consistent with that obtained by the above pulsed neutron experiment. However, the magnitude of the former correlated component was reduced with an increase in the subcriticality and eventually this component became almost white at deeply subcritical state ranging in the multiplication factor under 0.95. Consequently, the determination of the decay constant from the correlated component was impossible under such a subcritical state. As data analysis method for the beam trip experiment, both the conventional integral count method and the least-squares inverse kinetics method (LSIKM) were employed. The LSIKM analysis led to the consistent subcriticality with that obtained by the pulsed neutron experiment, while the integral count method significantly underestimated the subcriticality. This underestimation originated from a residual background count, which was maintained after the beam trip. The LSIKM was mostly not influenced by such a slight count rate. © 2013 Atomic Energy Society of Japan.
  • Sin-Ya Hohara; Masayo Inagaki; Hirokuni Yamanishi; Genichiro Wakabayashi; Wataru Sugiyama; Tetsuo Itoh
    Radiation Monitoring and Dose Estimation of the Fukushima Nuclear Accident Springer Japan 103 - 113 2014/01 [Refereed]
     
    The Kinki University Atomic Energy Research Institute investigated radioactive contamination resulting from the Fukushima Daiichi Nuclear Power Plant accident in urban areas of Fukushima City, Fukushima Prefecture, Japan. Activity measurement of the surface soil and a survey of the dose rate distribution in urban areas were performed. From the results of this research, dose rate changes in paved areas became clear, and gradients of the dose rate decrease for different paving materials were measured and analyzed.
  • Atsushi Sakon; Kengo Hashimoto; Wataru Sugiyama; Hiroshi Taninaka; Cheol Ho Pyeon; Tadafumi Sano; Tsuyoshi Misawa; Hironobu Unesaki; Takaaki Ohsawa
    Journal of Nuclear Science and Technology 50 (5) 481 - 492 0022-3131 2013/05 
    A series of power spectral analyses for a thermal subcritical reactor system driven by a pulsed 14 MeV neutron source was carried out at Kyoto University Critical Assembly (KUCA), to determine the prompt-neutron decay constant of the accelerator-driven system (ADS). The cross-power spectral density between time-sequence signal data of two neutron detectors was composed of a familiar continuous reactor noise component and many delta-function-like peaks at the integral multiple of pulse repetition frequency. The prompt-neutron decay constant inferred from the reactor noise component of the cross-power spectral density was consistent with that obtained by a pulsed neutron experiment. However, the reactor noise component of the auto-power spectral density of each detector was hidden by a white chamber noise in the higher-frequency range and this feature resulted in a considerable underestimation of the decay constant. For several runs with a low pulse-repetition frequency, furthermore, we attempted to infer the decay constant from point data of the delta-function-like peaks. The analysis for a run under a slightly subcritical state resulted in the consistent decay constant; however, those for other runs under significantly subcritical states underestimated the decay constant. Considering the contribution of a spatially higher mode to the point data, the above underestimation was solved to obtain the consistent decay constant. While the Feynman-α formula for a pulsed neutron source is too complicated to be fitted directly to variance-to-mean ratio data, the present analysis on frequency domain is much simpler and the conventional formula based on the first-order reactor transfer function is available for fitting to power spectral density data. © 2013 Taylor and Francis Group, LLC.
  • Sakon Atsushi; Muhamad Aiman Bin Maarof; Hashimoto Kengo; Sugiyama Wataru; Pyeon Cheolho; Sano Tadafumi
    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan Atomic Energy Society of Japan 2013 (0) 131 - 131 2013 
    14MeVパルス中性子源により駆動された京都大学臨界集合体の未臨界炉体系において、未臨界度を2％から8％の間で設定し、2系統の中性子検出器信号間および、加速器ビーム電流系と中性子検出器信号間のクロスパワースペクトル密度を測定した。このクロスパワースペクトル密度のゲインと位相差から算出した即発減衰定数は、パルス中性子源による結果を再現した。
  • HOHARA SHIN'YA; INAGAKI MASAYO; YAMANISHI HIROKUNI; WAKABAYASHI GEN'ICHIRO; SUGIYAMA WATARU; ITO TETSUO
    近畿大学原子力研究所年報 近畿大学原子力研究所 48 11 - 21 0374-8715 2012/03 
    type:Departmental Bulletin Paper [Abstract] Residual heat removal system of Fukushima Daiichi Nuclear Plant was down at 11th March 2011, because of the Tohoku Region Pacific Coast Earthquake and the Tsunami come after the earthquake. The system down causes the meltdowns in Reactor 1, Reactor2 and Reactor3. As a result, a large amount of radioactive materials were released to general environment, and dose rates of Tohoku & Kanto area increased with the fallout of the radioactive materials. Kinki University Atomic Energy Research Institute has researched time series variations of dose rate distribution and contamination level in urban distracts of Tohoku Naka-Dori Area from the middle of April 2011. Results of the researches and the analyses are described in this paper. Hohara, Sin-ya
  • Hiroshi TANINAKA; Atsuko MIYOSHI; Kengo HASHIMOTO; Cheol Ho PYEON; Tadafumi SANO; Tsuyoshi MISAWA; Wataru SUGIYAMA; Takaaki OHSAWA
    Journal of Nuclear Science and Technology Informa UK Limited 48 (9) 1272 - 1280 0022-3131 2011/09
  • Hiroshi TANINAKA; Kengo HASHIMOTO; Cheol Ho PYEON; Tadafumi SANO; Tsuyoshi MISAWA; Hironobu UNESAKI; Wataru SUGIYAMA; Takaaki OHSAWA
    Journal of Nuclear Science and Technology Informa UK Limited 48 (6) 873 - 879 0022-3131 2011/06
  • Sakon Atsushi; Tomizuka Shingo; Hashimoto Kengo; Pyeon Cheolho; Sano Tadafumi; Misawa Tsuyoshi; Sugiyama Wataru
    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan Atomic Energy Society of Japan 2011 (0) 164 - 164 2011 
    パルスモード運転下の加速器により駆動された京都大学臨界集合体の未臨界炉体系において、検出器出力のパワースペクトル密度を測定した。このパワースペクトル密度から算出した即発減衰定数は、固定中性子源下での結果と一致した。
  • Tomizuka Shingo; Sakon Atsushi; Hashimoto Kengo; Sugiyama Wataru
    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan Atomic Energy Society of Japan 2011 (0) 152 - 152 2011 
    高次モード計算の源反復に対してWielandtの加速法を適用した。高速原型炉クラスの体系の空間高次モード計算に適用した結果、基本モードのみならず高次モードの源反復の収束の著しい加速が確認された。
  • Reductive atmosphere of supercritical water with RuO2 resulting in TcO2 colloid: Spectroscopic, morphological and crystallographic study on solutions and precipitates in Hasteroy C-22
    T. Yamamura; K. Yubuta; I. Satoh; Y. Yoshida; Y. Shiokawa; T. Sekine; W. Sugiyama; K.-C. Park; H. Tomiyasu
    The Journal of Supercritical Fluids 43 317  2007 [Refereed]
  • T. Yamamura; I. Satoh; W. Sugiyama; M. Takahashi; Y. Shiokawa; H. Tomiyasu; T. Ohtsuki
    Reseach Report of Laboratory of Nuclear Science 東北大学大学院理学研究科附属原子核理学研究施設 38 48 - 53 0385-2105 2005 [Refereed]
     
    The present investigation indicates that during the decomposition of laminate sheeting, the produced gas contains no radioactivity in any run. The distribution of Fe, Co, and Sr was determined by radiometric analysis after laminate sheeting was decomposed using supercritical water mixed with RuO_2. Iron, cobalt and strontium were recovered as solids after the present supercritical-water reaction by the addition of an excessive quantity of iron hydroxide before the reaction. In the case of strontium, almost all radioactivities were found in the liquid phase. However, by adding precipitate reagents to the liquid phase obtained in the reaction, strontium can be recovered in the solid phase. This method should be a very effective way to decompose the nonflammable organic materials of LLW generated by nuclear power plants.
  • Behavior of Technetium in Supercritical Water. Distribution to liquid, solid phases and onto metal surfaces
    T. Yamamura; I. Satoh; N. Okuyama; Y. Shiokawa; T. Sekine; W. Sugiyama; K.-C. Park; H. Tomiyasu
    Journal of Nucear and Radiochemical Sciences 6 233  2005 [Refereed]
  • Chemical states in oxides films on stainless steel treated in supercritical water: Study by factor analysis of X-ray photoelectron spectra
    T. Yamamura; N. Okumura; Y. Shiokawa; M. Oku; H. Tomiyasu; W. Sugiyama
    Journal of The Electrochamical Society 152 B540  2005 [Refereed]
  • 酸化ルテニウム触媒超臨界水による放射性廃棄物処理
    杉山亘; 岡田英嗣; 杉田雄二; 朴基哲; 冨安博; 山村朝雄
    火力原子力発電 57 29  2005 [Refereed]
  • An extreme disposition method for low-level radioactive using supercritical water (3)
    W. Sugiyama; T. Yamamura; K.-C. Park; H. Tomiyasu; Y. Shiokawa; H. Okada; Y. Sugita
    Progress in Nuclear Energy 47 29  2005 [Refereed]
  • Recovery of radioactivity as solids from nonflammable organic low-level radioactive wastes using supercritical water mixed with RuO2
    W. Sugiyama; T. Yamamura; K.-C. Park; H. Tomiyasu; I. Satoh; Y. Shiokawa; H. Okada; Y. Sugita
    The Journal of Supercritical Fluids 25 240  2005 [Refereed]
  • Decomposition of Radioactive Organic Wastes with Supercritical Water Medium Containing RuO2
    W. Sugiyama; K.-C. Park; T. Yamamura; H. Okada; Y. Sugita; H. Tomiyasu
    Journal of NUCLEAR SCIENCE and TECHNOLOGY 2 42  2005 [Refereed]
  • I. Satoh; T. Yamamura; N. Okuyama; Y. Shiokawa; M. Takahashi; T. Sekine; W. Sugiyama; K. C. Park; H. Tomiyasu
    CYRIC Annual Report Cyclotron and Radioisotope Center, Tohoku University 2004 95 - 99 2004 [Refereed]
  • Excitation and deexcitation processes of Eu(Ⅲ) benzo-crown-5 complex studied on comparing with its coordination sphere
    T. Yamamura; W. Sugiyama; H. Hotokezaka; M. Harada; H. Tomiyasu; Y. Nakamura
    Inorganica Chimica Acta 320 75  2001 [Refereed]
  • Study on a nuclear fuel reprocessing system based on the precipitation method in mild aqueous solutions
    Y. Asano; N. Asanuma; T. Ito; M. Kataoka; S. Fujino; T. Yamamura; W. Sugiyama; H. Tomiyasu
    American Nuclear Society, Nuclear Technology 120 198  1997 [Refereed]

MISC

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    Date (from‐to) : 2012/04 -2015/03 
    Author : SUGIYAMA Wataru
     
    In nuclear power stations, rubber groves and tapes made of polyvinyl chloride are used to minimize the radiation damage of workers. Once-through use is applied for these materials in spite of the incombustibility and, therefore, each site has recently suffered from increases in the amount of incombustible wastes. To overcome the problem, decomposition of such incombustible solid materials was examined by using supercritical or subcritical water in this study. One of the advantages of this method is that nothing except water should be added for the treatment, which greatly contributes to the suppression of generation of the secondary wastes. As a result of the experiments, these materials were found to be decomposed to liquid under some conditions. In addition, an IR analysis identified the liquid as some forms of natural oil. This means that the proposed method is promising not only to the decomposition of incombustible wastes but also to the recovery of useful fuels.

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