著者

石山 新太郎 山口 克彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.799, pp.718-725, 2013 (Released:2013-03-25)

参考文献数

6

被引用文献数

1 1

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Prototype remotely-operated vehicle equipped with high resolution TV monitor and underwater radiation measuring instrument was developed and actual condition of contaminated soil in the regulation pond in Fukushima was investigated. Remarkable contaminated point was observed beneath rainwater outfall of impounding reservoir(Length×Width×Depth; 112m×30m×3.5m) in the order of 3.3~5.24μSv/h. It is found that contaminated small particles in the order of 1-3mm are deposited in the polluted mud at the bottom of the reservoir and suspended by disturbance of water flow, and the contaminated zones in the order of 0.75-3.5μSv/h are distributed in a patchy fashion caused by confluent of outfall in the demarcated region(10m×10m×10m).

著者

宇賀地 弘和 奥 達雄 石山 新太郎 衛藤 基邦

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.62, no.593, pp.10-17, 1996-01-25

参考文献数

9

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Since carbon fiber reinforced carbon composite (C/C composite) materials have good mechanical properties at high temperature and low radioactivity under irradiated conditions, they have been used as the plasma-facing components in fusion facilities. Efficient utilization of these mechanical properties will lead to the use of c/c composite materials, these materials are expected for use as control rods for gas-cooled rectors and irradiating capsules. In the case of using c/c composite materials as the structural components, it is very important to evaluate the mechnical and thermal properties as well as fracture behavior. For structural components used in a reactor core, it is necessary to evaluate neutron-irradiation effects on these materials. However evaluation of these effects has been difficult, thus data on irradiated c/c composite materials are lacking. In this study, three kinds of c/c composite (CC-312, CX2002U and MCI) made of different fiber materials were irradiated under the condition of maximum neutron fluence of 2×10^<25> n/m^2 and maximum irradiating temperature of 1200℃, and the relationship between change of mechanical properties due to irradiation and the constitution of c/c composite materials was evaluated. In the case of CC-312 made of PAN fiber, Young's modulus changed slightly and bending strength after irradiation. In the case of CX2002U made of rayon fiber, Young's modulus and bending strength increased after irradiation. In the case of MCI made of pitch fiber, Young's modulus increased after irradiation, but bending strength decreased slightly after irradiation. These results enable the elucidation of the relationship between properties of fiber meterials and irradiation effect on c/c composite materials.