Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Fukui, Katsunori*; Hashiba, Kimihiro*; Matsui, Hiroya; Kuwabara, Kazumichi; Ozaki, Yusuke
JAEA-Research 2016-014, 52 Pages, 2016/09
JAEA-Research-2016-014.pdf:7.19MB
With respect to high-level radioactive waste disposal, knowledge of the long-term mechanical stability of shafts and galleries excavated in rock is required, not only during construction and operation but also over a period of thousands of years after closure. On the other hand, it is known that rock and the rock mass surrounding the disposal gallery shows time dependent behavior such as creep or the stress-relaxation. It becomes the issue in the stability evaluation of the disposal gallery to grasp the behavior. In order to solve this issue, we pushed forward research development. we pushed forward research development. In the fiscal year of 2015, the creep testing machine for Tage tuff was moved to the new building. The creep test was continuously conducted and the total testing time exceeded 17 years. The testing equipment and procedure were examined to investigate the deformation, failure and time-dependency of rock under wet conditions and between room temperature and 100
C. The long-term strength of rock under triaxle stress state was researched with the aid of laboratory testing results and in situ stress measurement.
Ishigami, Tsutomu; Shimada, Taro
Journal of Nuclear Science and Technology, 52(9), p.1186 - 1204, 2015/09
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)In the field of decommissioning of nuclear facilities, a reliable method for ensuring compliance with the criterion of site release is an important technical issue to be resolved in Japan. Considering that kriging can consider the spatial correlation of radioactivity concentrations, we propose a method of applying kriging to ensure compliance with the site release criterion. Estimated radioactivity concentrations exhibit uncertainty, which results in a certain probability of the occurrence of decision errors regarding site release. We describe a method for calculating the uncertainty and establish a minimum number of measurement points required. We applied the proposed method and a conventional statistical method to two sample cases. It was observed that the proposed method appropriately estimated the mean radioactivity concentration and led to an efficient measurement requiring fewer measurement points relative to the conventional method when spatial correlation existed.
Ise, Hideo*; Izaki, Makoto*; Oishi, Haruo*; Mori, Seiji*; Ako, Kentaro*; Moriyama, Hisashi*; Kagaya, Hiroaki*; Kobayashi, Masami*; Taguchi, Ko*; Shibanuma, Kiyoshi
FAPIG, (159), p.10 - 14, 2001/11
no abstracts in English
Shibata, Katsuyuki; Yasuda, Yuji; Onizawa, Kunio; Miyazono, S.
Structural Mechanics in Reactor Technology,Vol.G, p.461 - 466, 1987/00
no abstracts in English
