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Aoki, Katsunori; Yamanaka, Hiroki*; Watanabe, Kazuhiko*; Sugihara, Kozo
JAEA-Data/Code 2020-018, 45 Pages, 2021/02
JAEA-Data-Code-2020-018.pdf:4.54MB
JAEA-Data-Code-2020-018-appendix(DVD-ROM).zip:6.8MB
Mizunami Underground Research Laboratory (MIU) Project is pursued by Japan Atomic Energy Agency (JAEA) in the crystalline host rock (granite) as a part of geoscientific study of JAEA, and underground facilities of MIU are constructed down to 500m blow the ground surface. As small amount of Uranium is normally contained in granite, high concentration of radon is sometimes detected in the air of the underground facilities constructed in granitic rocks depending on their ventilation conditions. Radon concentrations in underground facilities of MIU have been measured according to the excavation progress of underground facilities or the change of ventilation system. It is recognized that the data obtained by the actual measurement of radon concentration in such underground facilities are rare and valuable. This repot summarizes the measured data from fiscal 2010 to fiscal 2020, together with the information of ventilation conditions and air temperature which affect radon concentrations in underground facilities. The variation of the equilibrium factors of radon is also examined with the actually measured data. As a result, it has been found that radon concentration in the drift is high in summer and low in winter according to the natural ventilation caused by the seasonal temperature difference between in and out of the underground facilities. Furthermore, the temporary increase in the equilibrium factor of radon in the drift at the start of ventilation is supposed to be due to the aerosol increase by the ventilation flow, such as the dust blown up.
Ishii, Yoji; Watanabe, Kazuhiko; Kamiya, Akira; Hayano, Akira; Mikake, Shinichiro; Takeuchi, Shinji; Ikeda, Koki; Yamamoto, Masaru; Sugihara, Kozo
JAEA-Technology 2010-044, 92 Pages, 2011/02
JAEA-Technology-2010-044.pdf:11.73MB
The "Mizunami Underground Research Laboratory" has been carrying out scientific research in granite to establish the technological basis for high-level radioactive waste disposal. To get reliable information on the rock mass geology and hydrogeology and on the bedrock conditions, a pilot borehole investigation was carried out before sinking the ventilation shaft. During this investigation, a zone with high hydraulic head and low hydraulic conductivity was observed at around GL-400m. To reduce water inflow during excavation, pre-excavation grouting with micro-fine cement was done in this region before sinking the Ventilation Shaft. Despite the high hydraulic head and the low hydraulic conductivity, effective reduction of water-inflow was achieved.
Isayama, Akihiko; Sakakibara, Satoru*; Furukawa, Masaru*; Matsunaga, Go; Yamazaki, Kozo*; Watanabe, Kiyomasa*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; Tamura, Naoki*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 86(6), p.374 - 377, 2010/06
no abstracts in English
Osakabe, Masaki*; Shinohara, Koji; Toi, Kazuo*; Todo, Yasushi*; Hamamatsu, Kiyotaka; Murakami, Sadayoshi*; Yamamoto, Satoshi*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 85(12), p.839 - 842, 2009/12
no abstracts in English
Idomura, Yasuhiro; Yoshida, Maiko; Yagi, Masatoshi*; Tanaka, Kenji*; Hayashi, Nobuhiko; Sakamoto, Yoshiteru; Tamura, Naoki*; Oyama, Naoyuki; Urano, Hajime; Aiba, Nobuyuki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 84(12), p.952 - 955, 2008/12
no abstracts in English
Yamauchi, Emiko*; Watanabe, Ritsuko; Oikawa, Miyoko*; Fujimoto, Hirofumi*; Yamada, Akinori*; Saito, Kimiaki; Murakami, Masahiro*; Hashido, Kazuo*; Tsuchida, Kozo*; Takada, Naoko*; et al.
Journal of Insect Biotechnology and Sericology, 77(1), p.17 - 24, 2008/02
The frequency of single strand breaks (SSBs) occurring on both strands of the pBR322 plasmid DNA region flanked by a pair of primers used for polymerase chain reaction (PCR) amplifications was determined after irradiation with 
Cs 
-rays. We refined that real time PCR is suitable for the detection and quantitative analysis of SSBs caused by -ray irradiation. The utility of this approach was also supported by the comparison of the practical experimental data with the Monte Carlo simulation. The potential application of this PCR method for the detection of genomic DNA damage was also confirmed.
Tochio, Daisuke; Watanabe, Shuji; Motegi, Toshihiro; Kawano, Shuichi; Kameyama, Yasuhiko; Sekita, Kenji; Kawasaki, Kozo
JAEA-Technology 2007-014, 62 Pages, 2007/03
JAEA-Technology-2007-014.pdf:9.74MB
The rise-to-power test of the High Temperature Engineering Test Reactor (HTTR) was begun in April 2000. The reactor thermal power of 30 MW, which is the maximum thermal power of the HTTR, and the reactor outlet coolant temperature of 850
C in normal operation was achieved in middle of December 2001. After that reactor thermal power of 30 MW a reactor outlet coolant temperature of 950C was achieved in the final rise-to-power test at April 2004. After receiving the operation permit, the safety demonstration tests were conducted to demonstrate inherent safety features of the HTGRs. This paper summarizes the HTTR operating experiences for five years since rise-to-power test that were catalogued into three categories, (1) Operating experience pertaining to new gas cooled reactor design, (2) Operating experience for improvement of the performance, (3) Operating experience due to fail of system and components.
Fukuda, Seiji; Kato, Jinzo; Onishi, Takeshi; Watanabe, Kozo; Okubo, Katsuichi; Ouchi, Masafusa; Isozaki, Hiroshi; Seki, Mamoru; Mito, Norio; Tsuruo, Akira; et al.
JAERI 1028, 55 Pages, 1962/10
no abstracts in English
Miya, Naoyuki; Watanabe, Daisuke*; Sakawa, Yoichi*; Shibahara, Takahiro*; Sugiyama, Kazuyoshi*; Shoji, Tatsuo*; Yamazaki, Kozo*; Masaki, Kei; Tanabe, Tetsuo*
no journal, ,
no abstracts in English
Sakawa, Yoichi*; Watanabe, Daisuke*; Shoji, Tatsuo*; Yamazaki, Kozo*; Masaki, Kei; Tanabe, Tetsuo*
no journal, ,
no abstracts in English
Watanabe, Daisuke*; Sakawa, Yoichi*; Shoji, Tatsuo*; Yamazaki, Kozo*; Masaki, Kei; Tanabe, Tetsuo*
no journal, ,
no abstracts in English
