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Tanaka, Yoshihiro*; Kametaka, Masao*; Okazaki, Kazuhiko*; Suzuki, Kazushige*; Seshimo, Kazuyoshi; Aoki, Kazuhiro; Shimada, Koji; Watanabe, Takahiro; Nakayama, Kazuhiko
Oyo Chishitsu, 59(1), p.13 - 27, 2018/04
This paper aims to develop a methodology for understanding the fault activity by observing exposed fault planes without covering younger strata. Based on purpose, faults developed in relatively homogeneous rocks such granitic types are investigated as follows; Gosuke Dam upstream outcrop of Gosukebashi Fault and Funasaka-nishi outcrop of Rokkou Fault were selected for the study of an active fault; and K-3 outcrop of Rokkou Houraikyo Fault was chosen for a non-active fault.
Shimada, Koji; Kametaka, Masao*; Nakayama, Kazuhiko; Seshimo, Kazuyoshi; Tanaka, Yoshihiro; Hayashi, Toshio*; Tanaka, Yukumo; Shimogama, Kota*; Okazaki, Kazuhiko*
Chishitsugaku Zasshi, 119(11), p.727 - 731, 2013/11
Staples for a stapler can be used as a frame of a small oriented sample taken from fragile and scarce fault gouge. The fault gouge was slotted for staples of an insert. Staples are a group of about ten or less ones holding right-angled three small surfaces. Pre-oriented staples set the slot would remove then presented for the SEM observation. Only a knife, some glues and simple equipment are needed for the method in the field or laboratories.
Ashida, Takashi; Miyamoto, Kazuyuki; Okazaki, Yoshihiro*; Ito, Hideaki
JAEA-Technology 2012-047, 106 Pages, 2013/06
JAEA-Technology-2012-047.pdf:11.09MB
JAEA-Technology-2012-047-appendix(CD-ROM).zip:15.46MB
In the experimental fast reactor Joyo, failure of disconnecting the irradiation test subassembly MARICO-2 (Material Testing Irradiation Rig with Temperature Control) was occurred and top of the MARICO-2 test subassembly was bent onto the in-vessel storage rack. As a result of this incident, the operation area of rotating plug for the fuel exchange in Joyo is limited. The replacement of the damaged UCS and retrieving the bent MARICO-2 are required to Joyo restoration. This report describes about investigations and some tests to know the status of MARICO-2 test subassembly and the optimized detail design of retrieval device reflecting those results.
Imaizumi, Kazuyuki; Saito, Takakazu; Tobita, Shigeharu; Nagai, Akinori; Kitamura, Ryoichi; Okazaki, Yoshihiro
JAEA-Technology 2012-027, 49 Pages, 2012/08
JAEA-Technology-2012-027.pdf:7.07MB
In-Vessel Observations (IVO) techniques for Sodium cooled Fast Reactors (SFRs) are important in confirming its safety and integrity. In order to secure the reliability of IVO techniques, it was necessary to demonstrate the performance under the actual reactor environment with high temperature, high radiation dose and remained sodium. During the investigation of an incident occurred in Joyo, the following observation systems were specifically developed for Joyo. And the following two observations were conducted. (1) Simple overhead observation using a standard video camera for the top of the sub-assemblies and the in-vessel storage rack (2) Narrow space observation using remote handling device equipped with radiation-resistant fiberscope for the bottom face of the upper core structure. As a result, the observations under the actual reactor environment were successfully made even in the narrow space in the reactor vessel and the results provided useful information on incident investigations and planning of restoration work.
Naito, Hiroyuki; Itagaki, Wataru; Okazaki, Yoshihiro; Imaizumi, Kazuyuki; Ito, Chikara; Nagai, Akinori; Kitamura, Ryoichi; Shamoto, Naoki*; Takeshima, Yoshiyuki*
JAEA-Technology 2012-009, 100 Pages, 2012/05
JAEA-Technology-2012-009.pdf:9.89MB
The radiation characteristics of image fiber and light guide fiber were evaluated to develop a high radiation resistant fiberscope for the fast reactor in-vessel observation. It is known that a pure silica core fiber has a high radiation resistance and radiation resistance is influenced with impurities in silica. Moreover it is necessary to change the clad material of the light guide fiber because that of the current light guide fiber is acrylate, which is weak against radiation. Hence the improved fibers consist of a pure silica core with 1,000 ppm OH and fluorine-doped silica clad. As a result of a 
irradiation test, we confirm that OH inhibits the generation of the precursor by irradiation. About the clad material, we confirmed that the transmission loss of the fluorine-doped silica clad fiber is smaller than that of the acrylate clad fiber. About the mechanical strength of a fiber, we confirmed that there is no weakening the strength of the fiber and no exfoliation of the coating from the glass. In this study, we discovered the fiber which consists of a pure silica core with 1,000 ppm OH and fluorine-doped silica clad has a high radiation resistance and it is possible to observe using this fiber under the 200 
C after 5
10
Gy irradiation.
Takahashi, Yoshihiro*; Takeyasu, Hidenori*; Okazaki, Yuji*; Hirao, Toshio; Onoda, Shinobu; Oshima, Takeshi
Proceedings of 9th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-9), p.173 - 175, 2010/10
no abstracts in English
Togashi, Yoshihiro; Miyauchi, Masakatsu; Sonobe, Tamotsu; Niitsuma, Yasushi; Nakajima, Takayuki; Haga, Takahisa*; Tanoue, Takahiro; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; et al.
JAERI-Tech 2000-032, p.25 - 0, 2000/03
JAERI-Tech-2000-032.pdf:1.45MB
no abstracts in English
Fujine, Sachio; Murata, Mikio; Abe, Hitoshi; Takada, Junichi; Tsukamoto, Michio; Miyata, Teijiro*; Ida, Masaaki*; Watanabe, Makio; Uchiyama, Gunzo; Asakura, Toshihide; et al.
JAERI-Research 99-056, p.278 - 0, 1999/09
JAERI-Research-99-056.pdf:22.73MB
no abstracts in English
Sonoda, Takashi; Togashi, Yoshihiro; Miyauchi, Masakatsu; Okazaki, Shuji*
JAERI-Tech 99-043, 16 Pages, 1999/05
no abstracts in English
Okazaki, Yoshihiro; Ashida, Takashi; Miyamoto, Kazuyuki; Kaito, Yasuaki; Ito, Hideaki
no journal, ,
no abstracts in English
Aoyama, Takafumi; Ito, Chikara; Araki, Yoshio; Naito, Hiroyuki; Iwata, Yoshihiro; Okazaki, Koki*; Harano, Hideki*; Watanabe, Kenichi*; Iguchi, Tetsuo*; Takegawa, Nobuyuki*; et al.
no journal, ,
no abstracts in English
Ashida, Takashi; Okazaki, Yoshihiro; Miyamoto, Kazuyuki; Noguchi, Koichi; Ito, Hideaki
no journal, ,
The 15th periodic inspection of Joyo commenced in May 2007 with the Fuel Handling Machine (FHM) being set up on the Rotating Plug (R/P) for refueling in June. When the R/P was taken down, measuring the load of the Hold-Down Shaft (HDS) revealed an abnormal decrease above the in-vessel storage rack (IVS). As a result of the observations, it was discovered that the top of the irradiation test S/A "MARICO-2"had bent onto the IVS as an obstacle, and had damaged the Upper Core Structure (UCS). The other action items in the restoration work, which are design of UCS and MARICO-2 handling device will be investigated in detail designs. The experience obtained through the restoration work in Joyo will provided valuable insights into possible further improvements and verifications for in-vessel inspection and repair techniques in SFRs.
Naito, Hiroyuki; Itagaki, Wataru; Ito, Chikara; Okazaki, Yoshihiro; Nagai, Akinori; Shamoto, Naoki*; Takeshima, Yoshiyuki*
no journal, ,
no abstracts in English
Takeyasu, Hidenori*; Okazaki, Yuji*; Ogura, Shunta*; Otani, Takumi*; Takahashi, Yoshihiro*; Hirao, Toshio; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi
no journal, ,
no abstracts in English
Aoyama, Takafumi; Ito, Chikara; Naito, Hiroyuki; Iwata, Yoshihiro; Harano, Hideki*; Okazaki, Koki*; Araki, Yoshio*; Watanabe, Kenichi*; Iguchi, Tetsuo*; Takegawa, Nobuyuki*; et al.
no journal, ,
no abstracts in English
Hirao, Toshio; Onoda, Shinobu; Makino, Takahiro; Takahashi, Yoshihiro*; Takeyasu, Hidenori*; Okazaki, Yuji*; Abo, Satoshi*; Masuda, Naoyuki*; Takai, Mikio*; Oshima, Takeshi
no journal, ,
no abstracts in English
Naito, Hiroyuki; Itagaki, Wataru; Okazaki, Yoshihiro; Imaizumi, Kazuyuki; Kitamura, Ryoichi; Shamoto, Naoki*; Takeshima, Yoshiyuki*
no journal, ,
no abstracts in English
Ashida, Takashi; Ito, Hideaki; Nagai, Akinori; Kitamura, Ryoichi; Okazaki, Yoshihiro*
no journal, ,
no abstracts in English
Nakayama, Kazuhiko; Shimada, Koji; Seshimo, Kazuyoshi; Tanaka, Yoshihiro; Kametaka, Masao*; Okazaki, Kazuhiko*; Shimogama, Kota*; Hayashi, Toshio*
no journal, ,
no abstracts in English
Kametaka, Masao*; Nakayama, Kazuhiko; Aoki, Kazuhiro; Seshimo, Kazuyoshi; Shimada, Koji; Tanaka, Yoshihiro; Okazaki, Kazuhiko*; Funato, Akio*; Hayashi, Toshio*
no journal, ,
no abstracts in English
