Search Results 1-20 of 20

  • Measures to remove the LWR core debris and its criticality safety management:(3)Work process and ciriticality safety evaluation of core debris removal and its interim storage  [in Japanese]

    Takaki Naoyuki , Okazaki Dai , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    前回学会で報告した福島第一原発の溶融燃料取り出し方策に関し、溶融燃料の粉砕・回収から保管・貯蔵までの全体の工程構成を示すとともに、各段階での臨界安全性を評価した。全ての工程で未臨界状態を確実にするための中性子吸収材の利用方法も検討した。

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2013s(0), 157, 2013

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  • Measures to remove the LWR core debris and its criticality safety management:(4)Criticality safety evaluation during core debris removal and its interim storage  [in Japanese]

    Okazaki Dai , Takaki Naoyuki , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    本発表では筆者らが提案する溶融燃料取り出し方策において、溶融燃料の粉砕・回収から保管・貯蔵までの各段階での臨界安全性を評価するとともに、中性子吸収材の効果を示す。

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2013s(0), 158, 2013

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  • Measures against re-criticality of the LWR core during meltdown:(3)Effect of the floatable hollow boron particles on the reactivity safety during core melt down  [in Japanese]

    Shindo Yuta , Takasaki Shin , Takaki Naoyuki , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    軽水炉炉心溶融時に溶融燃料の空隙に適度な水が存在する大きなデブリ領域が形成されると再臨界が起こる可能性がある。再臨界の予防にはホウ酸水を注入する方法があるが、デブリの外側にしか存在できないため、ホウ酸水が中性子を吸収することによる再臨界予防効果は小さい。しかもホウ酸水濃度はその後の注水により薄まるため、補い続ける必要がある。そこで筆者らは前報において、水に浮く中空ボロン粒子を事故発生直後に炉内に投 …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2013s(0), 160, 2013

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  • Measures to remove the LWR core debris and its criticality safety management:The boron pellet made by powder metallurgy process, and the gel-like neutron absorption material  [in Japanese]

    Tominaga Masanao , Ishijima Zenzo , Okazaki Dai , Takaki Naoyuki , Matsumoto Tetsuo

    著者らは軽水炉の溶融燃料取り出し・一時貯蔵時の臨界安全性を高めるための中性子吸収材として、ペレット状ボロンおよびゲル状ボロンを考案し試作した。前者は粉末冶金法によりボロン粉末を直径・高さとも10mm程度の円柱状に成形したもので、粉砕した溶融燃料中に混入させることにより、溶融燃料取り出し時およびその後の保管時にも失われることなく有効な中性子吸収能力を長期にわたり維持する。後者はボロン粉末を疎水性の有 …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2013s(0), 159, 2013

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  • Measures against re-criticality of the LWR core during meltdown:(2) Floatable hollow boron particles manufacturing by powder metallurgy  [in Japanese]

    Shindo Yuta , Kato Takashi , Takaki Naoyuki , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    筆者らは軽水炉の炉心溶融時に燃料溶融が水面上に露出した部分から起こることに着目し、再臨界予防のために水に浮く中空ボロン粒子を事故発生直後に炉内に投入する方法を提案する。本発表では、水に浮く中空ボロン粒子の試作につき示す。ボロンの比重(約2.3)を考慮し平均外径1.5 mm、平均重量1.1 mg で水に浮く中空ボロン粒子を粉末冶金法で試作した。B<sub>4</sub>C は …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2012f(0), 151, 2012

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  • Measures against re-criticality of the LWR core during meltdown:(1) Effect of the floatable hollow boron particles on the reactivity safety  [in Japanese]

    Shindo Yuta , Kato Takashi , Takaki Naoyuki , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    軽水炉炉心溶融時に溶融燃料の空隙に適度な水が存在する大きなデブリ領域が形成されると再臨界が起こる可能性がある。再臨界の予防にはホウ酸水を注入する方法があるが、デブリの外側にしか存在できないため、ホウ酸水が中性子を吸収することによる再臨界予防効果は小さい。しかもホウ酸水濃度はその後の注水により薄まるため、補い続ける必要がある。そこで筆者らは溶融燃料が水面上に露出した部分から起こることに着目し、水に浮 …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2012f(0), 150, 2012

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  • Measures to remove the LWR core debris and its criticality safety evaluation:(2) Criticality safety evaluation during core debris removal  [in Japanese]

    Okazaki Dai , Shindo Yuta , Matsumoto Tetsuo , Takaki Naoyuki , Tominaga Masanao , Ishijima Zenzo

    軽水炉燃料はもともと低濃縮度燃料であることから、溶融燃料取り出し作業において臨界になることは殆どないと考えられるが、燃料が格納容器にまで漏れ出すような大規模な炉心溶融は前例が無く、その溶融燃料の取り出しは世界的にも経験のない困難な取り組みのため、安全管理上は臨界安全にも十分に配慮して万全の防止策をとることは必須である。本発表では筆者らが提案する溶融燃料取り出し方策において、溶融燃料の粉砕および粉砕 …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2012f(0), 149, 2012

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  • Measures to remove the LWR core debris and its criticality safety evaluation:(1) General remarks and measures to remove the core debris  [in Japanese]

    Takaki Naoyuki , Okazaki Dai , Shindo Yuta , Matsumoto Tetsuo , Tominaga Masanao , Ishijima Zenzo

    原子炉圧力容器底部および原子炉格納容器底部に溜まった溶融燃料を遠隔操作により安全に取り出す方策につき示す。筆者らは原子炉圧力容器直径よりも小口径の回転プラグ状の架台を原子炉圧力容器内に挿入・固定し、これに搭載した溶融燃料吸引装置(水中削岩機と水中掃除機の組み合わせ)などにより溶融燃料およびデブリを取り出す方策を提案する。本装置では溶融燃料取り出しの際に、十分な中性子吸収能力をもち、かつ溶融燃料取り …

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2012f(0), 148, 2012

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  • Development of aluminum matrix composites for neutron absorbing material  [in Japanese]

    Kamimura Yusuke , Sonoda Masayuki

    Journal of Japan Institute of Light Metals 60(11), 619-621, 2010

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  • Mechanical Properties of 1%B-A6061-T6/T651 and A6061-T6/T651 Used for Basket of Transport and Storage Cask  [in Japanese]

    SHIMOJO Jun , AKAMATSU Hiroshi

    … Basket material of transport and storage cask is required to have not only a structural strength during transport and storage conditions, neutron absorbing function but also heat removal function. … The basket material is also preferable to be light in order to reduce the weight of cask because it is very important to improve the efficiency of transport and storage by increasing the number of fuel assemblies loaded in cask. …

    TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A 76(771), 1523-1525, 2010

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  • Local Structure around the Amino Group of Glycine Carbamate in Concentrated Aqueous Solutions

    Kameda Yasuo , Amo Yuko , Usuki Takeshi

    Neutron diffraction measurements were carried out on aqueous alkaline 2 mol % glycine heavy water solutions absorbing CO<sub>2</sub>. …

    Bulletin of the Chemical Society of Japan 82(12), 1485-1490, 2009

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  • ICONE15-10405 Development of Borated Aluminum Alloy with Stability at High Temperatures

    Okido Shinobu , Nakane Motoki , Hiranuma Takeshi , Okaniwa Shigeru , Kondo Takutoshi

    … A stainless steel and aluminum alloy containing neutron-absorbing materials is used as a basket that is a component of a partition plate for the spent fuel in the metal cask. … This material has not only high heat conductivity, but also high strength at high temperatures. …

    The Proceedings of the International Conference on Nuclear Engineering (ICONE) 2007.15(0), _ICONE1510-_ICONE1510, 2007

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  • Neutron Diffraction Studies on the Hydrogen-Bonded Structure of Water Molecules in Ion Exchange Resins

    Kameda Yasuo , Yamanaka Koji , Sasaki Motoya , Amo Yuko , Usuki Takeshi

    Neutron diffraction measurements were carried out for anion and cation exchange resins (AER and CER, respectively) absorbing H/D isotopically substituted water molecules in order to obtain structural information on the hydrogen-bonded network among water molecules within the resins. …

    Bulletin of the Chemical Society of Japan 79(7), 1032-1038, 2006

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  • Observation of Hydrogen Atoms in Nano and Amorphous Hydrogen Absorbing Materials by Neutron Scattering  [in Japanese]

    FUKUNAGA Toshiharu , ITOH Keiji

    Materia Japan 43(3), 225-231, 2004-03-20

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  • Invention of Materials and Structural Observation

    Fukunaga Toshiharu

    Neutron scattering techniques have been recognized to get structural information of materials. … In this writing I show briefly that structural information can play an important role to get seeds for invention of new materials through recent works of the hydrogen absorbing nano-graphite. … Therefore, material scientists can anticipate that J-PARC will give them the various kinds of structural properties of complex materials for planning new materials for human life. …

    hamon 14(1), 22-24, 2004

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  • Application of Advanced Neutron Absorbing Materials to Structural Material of Inner Basket of Storage Casks for High Burnup and MOX Spent Fuels  [in Japanese]

    AJIMA Tatsuro , KOSAKI Akio , INOHARA Yasuto , YOKOYAMA Hayaichi

    日本原子力学会誌 = Journal of the Atomic Energy Society of Japan 39(2), 156-165, 1997-02-28

    References (28)

  • Application of Advanced Neutron Absorbing Materials to Structural Material of Inner Basket of Storage Casks for High Burnup and MOX Spent Fuels.  [in Japanese]

    AJIMA Tatsuro , KOSAKI Akio , INOHARA Yasuto , YOKOYAMA Hayaichi

    … Advanced neutron absorbing structural materials, which contain high concentration of boron or enriched boron, such as (1) Borated stainless steel, (2) Borated aluminum alloy, (3) Borated composite (three layered clad plate composed of borated stainless steel/copper/borated stainless steel structure) were considered suitable for the structural material of the inner baskets.<br>Improvements of thermal conductivity and mechanical strength as well as neutron

    Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 39(2), 156-165, 1997

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  • Study on Neutron Absorbing Materials Using Organometallic Complexes  [in Japanese]

    Kayano Hideo , Hironori Ohno , Takagi Ryoko , Takaku Hiroshi , Hasegawa Yoshio

    … A new dispersion-type sintered neutron absorbing alloy has been developed. … An organometallic complex of highly neutron absorbing Gd, Sm and In is melted by heating to 200°C. … The resulting neutron absorbing material has thus high values of both hardness and mechanical strength at room temperature and also in ductility. …

    Journal of the Japan Society of Powder and Powder Metallurgy 26(6), 223-227, 1979

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  • Optimal Control of Steady State Neutron Flux Distribution in Slab Reactors

    KOGA Ryuji , HATTORI Yoshio , IWAZUMI Tetsuo

    … The algorithm is presented for seeking optimal control of the steady state neutron flux distribution making use of Pontryagin's Maximum Principle, for a one group model of the bare slab reactor as well as for a two group model of the reflected slab reactor, both of which are homogeneous except for the control material. …

    Journal of Nuclear Science and Technology 8(5), 267-276, 1971

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  • Radiation Shielding Properties of Glasses in the System Li<sub>2</sub>O-PbO-B<sub>2</sub>O<sub>3</sub>  [in Japanese]

    SUGIURA Toshio , MURAKAMI Keiichi , TANAKA Hirobumi , AKIMOTO Hidetoshi

    … have been investigated for the application as radiation shielding material. … This system is selected because of large cross section of boron for neutron, high absorption property of lead for gamma ray and favorable property of lithium in respect of secondary gamma ray.<br>The glass formation range determined in this system was fairly wide and twelve samples were prepared in this region. …

    Journal of the Ceramic Association, Japan 72(822), 99-103, 1964

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