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Morita, Hisashi; Daigo, Fumihisa; Sayato, Natsuki; Watahiki, Shunsuke; Kojima, Kazuki; Nakayama, Kazuhiko; Ide, Hiroshi
JAEA-Technology 2021-030, 166 Pages, 2022/05
JAEA-Technology-2021-030.pdf:3.65MB
When the roof of the JMTR Hot Laboratory (HL) building was repaired for rain leaks in January, 2015, thinning was found at one of the anchor bolts on base of the HL exhaust stack. Moreover, the thinning of some anchor bolts and gaps between the anchor bolt nuts and flange plate was found in the later investigation for the exhaust stack. Since the possibility of the exhaust stack collapsing cannot be denied, it was removed. Therefore, it became necessary to rebuild a new exhaust stack as soon as possible. The design of the new exhaust stack was based on the measures to prevent rainwater intrusion into the base, which was the cause of the thinning of the anchor bolts found in the investigation, and on the new regulatory standards established after the accident at the Fukushima Daiichi Nuclear Power Station. Furthermore, since the new exhaust stack corresponds to buildings and structures that must undergo building confirmation, the soundness of the new exhaust stack against seismic force and wind load was evaluated based on the Building Standards Law and the Stack Structure Design Guideline. This report described the basic design of the new exhaust stack.
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.
Nakayama, Takuya; Yagi, Naoto; Sato, Kazuhiko; Hinoda, Shingo; Nakagiri, Toshio; Morimoto, Yasuyuki; Umezawa, Katsuhiro; Sugitsue, Noritake
JAEA-Review 2018-005, 163 Pages, 2018/03
JAEA-Review-2018-005.pdf:72.95MB
The Ningyo-toge Environmental Engineering Center of JAEA has been working together with local communities for more than 60 years. Through our R&D projects on from uranium exploration to uranium enrichment as a part of the nuclear fuel cycle (i.e., front-end), we have accumulated experiences in the fields of management of uranium related technology. Taking advantage of such our potential, we will start new R&D program on "Research on Uranium and the Environment". In December 2016 we announced our new concept of the "Uranium and Environmental Research Platform" as a framework aimed at contributing to regional and international society through R&D programs (environmental research and uranium waste engineering research) that are needed to steadily carry out decommissioning of uranium handling facilities.
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.
Hayashi, Kenta; Nakamura, Takahisa; Takagi, Hisatsugu; Horie, Kaoru; Nakayama, Tamotsu; Hashimoto, Kazuhiko; Hayashi, Shoichi; Nakamura, Shinji; Takenaka, Shigeki; Ishizuka, Nobuo; et al.
Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07
JAEA and USDOE (Los Alamos National Laboratory (LANL)) have been collaborating on spent fuel measurements with a PNAR/SINRD NDA instrument at Fugen, in the course of the NGSI Spent Fuel Nondestructive Assay Project. In this collaboration, LANL's role has been to design and fabricate the detector (integrated PNAR and SINRD system), while JAEA's role has been to undertake the installation of the detector at the appropriate position in the spent fuel pool and to prepare for the actual measurements. In this paper we report the rehearsal of the measurement using a mock-up detector and a dummy fuel assembly in December 2012 and the plan of actual measurements in June 2013 (at the time of submission of this paper).
Isobe, Nobuhiro*; Sukekawa, Masayuki*; Nakayama, Yasunari*; Date, Shingo*; Otani, Tomomi*; Takahashi, Yukio*; Kasahara, Naoto; Shibamoto, Hiroshi*; Nagashima, Hideaki*; Inoue, Kazuhiko*
Nuclear Engineering and Design, 238(2), p.347 - 352, 2008/02
Times Cited Count：23 Percentile：78.72(Nuclear Science & Technology)The effect of ratcheting on fatigue strength was investigated in order to rationalize the strain limit as a design criterion of commercialized fast reactor systems. Ratcheting fatigue tests were conducted at 550
C. Duration of the ratchet straining was set for a certain number of strain cycles taking the loading condition of fast reactors into account, and the number of cycles for strain accumulation was defined as the ratchet-expired cycle. Fatigue lives decrease as the accumulated strain by ratcheting increases. Fatigue life reduction was negligible when the maximum mean stress was less than 25 MPa, corresponding to an accumulated strain of 2.2 percent. Accumulated strain is limited to 2 percent in the present design guidelines and this strain limit is considered effective to avoid reducing fatigue life by ratcheting. Micro-crack growth behaviors were also investigated in these tests in order to discuss the life reduction mechanisms in ratcheting conditions.
Kato, Takashi; Hamada, Kazuya; Kawano, Katsumi; Matsui, Kunihiro; Hiyama, Tadao; Nishida, Kazuhiko*; Honda, Tadaaki*; Taneda, Masanobu*; Sekiguchi, Shuichi*; Otsu, Kiichi*; et al.
ICEC16/ICMC Proceedings, p.127 - 130, 1996/00
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*; Okazaki, Kazuhiko*; Nakayama, Kazuhiko; Seshimo, Kazuyoshi; Aoki, Kazuhiro; Tanaka, Yoshihiro; Shimada, Koji; Suzuki, Kazushige*; Shimogama, Kota*; Inada, Noriyuki*
no journal, ,
The evaluation of an fault activity has been done by an observation of deformation of overlying strata of the fault. However, it is difficult to evaluate the activity where the fault zone appears only in a basement rock with no overlying strata. We have been carried out the observation of the fault zone to establish the method of evaluation of fault activity. We selected the outcrops through literature and surface geological survey. Examples of outcrops of active fault are outcrops of Gosukebashi Fault in the Rokko-Awaji Fault Zone and the Rokko Fault in the Arima-Takatsuki Tectonic Line, southern Hyogo Prefecture. An example of non-active fault is outcrop of the fault around the Rokko Horai-kyo in the northern Rokko Mountains. In this study, we focus on the easy evaluation method in the field, and described about suitability of observation of fault plane, in-situ experiments of hardness and color.
Isomi, Kazuhiko; Matsushima, Akira; Nakayama, Tamotsu; Ishiyama, Masahiro; Nakamura, Yasuyuki
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
Kametaka, Masao*; Sakai, Toru*; Inada, Noriyuki*; Tanaka, Yumiko*; Okazaki, Kazuhiko*; Suzuki, Yuji*; Aoki, Kazuhiro; Tanaka, Yoshihiro; Seshimo, Kazuyoshi; Nakayama, Kazuhiko
no journal, ,
no abstracts in English
Atsumi, Hiroyuki*; Masumoto, Kazuhiko*; Ishii, Tomoko*; Jo, Mayumi*; Nakayama, Masashi; Ono, Hirokazu
no journal, ,
In the vertical disposal concept of high level radioactive waste, it is important to evaluate influence of the groundwater inflow into the disposal pits against performance of buffer material as an artificial barrier because the inflow might cause the erosion of buffer material. The target of this study was to estimate the inflow control technique (e.g. grouting) around the disposal pits using numerical analysis. The model for the simulation should be a discrete fracture network model when the groundwater mainly flows along the fractures in the rock mass, therefore, the discrete fracture network model was selected to estimate the inflow control technique in this study. The results of numerical flow analysis showed that the effectiveness of grouting for the disposal pits and the impact of grouting for the other disposal pits or surrounding disposal tunnel could be evaluated quantitatively.
Shibamoto, Hiroshi; Inoue, Kazuhiko*; Takahashi, Yukio*; Nakamura, Kyotada*; Kasahara, Naoto; Nakayama, Yasunari*
no journal, ,
no abstracts in English
Matsushima, Akira; Nakayama, Tamotsu; Soejima, Goro; Takiya, Hiroaki; Isomi, Kazuhiko
no journal, ,
no abstracts in English
Ichijo, Tsubasa; Nakayama, Kazuhiko; Seshimo, Kazuyoshi; Kojima, Kazuki; Sakurai, Momoka
no journal, ,
no abstracts in English
Nakayama, Takuya; Osugi, Takeshi; Shimazaki, Takejiro; Abe, Tomohisa; Yagi, Naoto; Nakazawa, Osamu; Sato, Haruo*; Suzuki, Kazuhiko*
no journal, ,
The amount of hydrogen generated by the radiation of adjacent cement-solidified wastes, and its effect was evaluated by PHITS code, when dispose them. These results suggested that the amount of hydrogen generation was inhibited by increase the separation distance between the cement-solidified waste, and the waste of high radioactive concentration does not place continuously.
