Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Murata, Chinatsu; Kitahara, Masaru; Tanaka, Kiwamu; Amazawa, Hiroya; Takebe, Shinichi; Yamada, Osamu*; Kameo, Yutaka
Dekomisshoningu Giho, (62), p.20 - 31, 2020/09
On the basis of Act on Special Measures, municipalities stripped surface soil off the playground of park to decontaminate the soil which had been contaminated with radionuclides released from Fukushima Daiichi Nuclear Power Plant. To minimize the exposure dose of the residents, it was essential to decide safe disposal of the contaminated soil which has been stored at temporary storage areas. Therefore, the ministry of the Environment and Tokai-mura office required Japan Atomic Energy Agency (JAEA) to perform demonstration project of burying the contaminated soil generated by decontamination of public facilities in order to provide decision on the enforcement ordinance and guidelines of burying it. In this project, we acquired data of air dose rate and the personal exposure dose during transporting, burying, and storing the contaminated soil. In addition, we measured radioactivity concentration of dust collected from surroundings of the landfill and seepage water through contaminated soil.
Shobu, Nobuhiro; Kato, Masatoshi*; Takao, Tomoe*; Terashima, Daisuke*; Tanaka, Yoshie*; Shirasu, Hisanori*; Amazawa, Hiroya; Koibuchi, Hiroto; Nakata, Hisakazu
JAEA-Review 2013-028, 175 Pages, 2013/12
JAEA-Review-2013-028.pdf:10.13MB
JAEA has promoted near surface disposal project for low-level radioactive wastes generated from research, industrial and medical facilities. JAEA has carried out public information about the project. When some town meetings are held toward mutual understanding with the public more detailed and clear explanations for safety management of the project are needed especially. Therefore, the information provision method to make the public understand should be reviewed. Moreover, a survey should be carried out in order to get a sense of what the public knows, what it values and where it stands on nuclear energy and radiation issues, because the social environment surrounding nuclear energy and radiation issues has changed as a result of the accident at the Fukushima on March 11, 2011. This review clarified the points to keep in mind about public information on the project, and that public recognition or understanding toward nuclear energy and radiation was changed before and after the accident.
Asakura, Nobuyuki; Shinya, Kichiro*; Tobita, Kenji; Hoshino, Kazuo; Shimizu, Katsuhiro; Uto, Hiroyasu; Someya, Yoji; Nakamura, Makoto; Ono, Noriyasu*; Kobayashi, Masahiro*; et al.
Fusion Science and Technology, 63(1T), p.70 - 75, 2013/05
no abstracts in English
Asakura, Nobuyuki; Shinya, Kichiro*; Tobita, Kenji; Hoshino, Kazuo; Shimizu, Katsuhiro; Uto, Hiroyasu; Someya, Yoji; Nakamura, Makoto; Ono, Noriyasu*; Kobayashi, Masahiro*; et al.
Fusion Science and Technology, 63(1T), p.70 - 75, 2013/05
Times Cited Count：14 Percentile：72.01(Nuclear Science & Technology)Design study of poloidal field coil (PFC) locations and current distribution for the advanced divertor in the Demo tokamak reactor was presented. Concept of the super-X divertor (SXD) for Demo reactor has an outer divertor leg longer than the conventional divertor, and it extends outboard to increase both the target wetted area and connection length to the outer target (
). Equilibrium calculation code, TOSCA, was developed by introducing two parameters, i.e. super-X null radius (
) and a ratio of the poloidal flux at the super-X null to that at the separatrix (
). Some SXD magnetic configurations with minimal number of PFCs located outside toroidal field coil (TFC) were Demonstrated. Locations of the divertor target were also investigated. It was found that the flux expansion can be increased up to 4-10 depending on the target location and , and that SXD has an advantage to increase with . Thus, the divertor plasma temperature is expected to decrease at the same upstream plasma density. On the other hand, large currents for the divertor PFCs were necessary. Other arrangements of PFCs such as (1) larger and (2) inside TFC, can reduce the PFC currents.
Odaka, Hirokazu*; Ichinohe, Yuto*; Takeda, Shinichiro*; Fukuyama, Taro*; Hagino, Koichi*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; Watanabe, Shin*; Kokubun, Motohide*; et al.
Nuclear Instruments and Methods in Physics Research A, 695, p.179 - 183, 2012/12
Times Cited Count：23 Percentile：83.88(Instruments & Instrumentation)We have developed a new Si/CdTe semiconductor double-sided strip detector (DSD) Compton camera. The camera consists of a 500-
m-thick Si-DSD and four layers of 750-m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 degrees at 356 keV and 3.5 degrees at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.
-ray cameraTakeda, Shinichiro*; Ichinohe, Yuto*; Hagino, Koichi*; Odaka, Hirokazu*; Yuasa, Takayuki*; Ishikawa, Shinnosuke*; Fukuyama, Taro*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; et al.
Physics Procedia, 37, p.859 - 866, 2012/10
Times Cited Count：23 Percentile：98.4(Physics, Applied)By using new Compton camera consisting of silicon double-sided strip detector (Si-DSD) and CdTe-DSD developed for the ASTRO-H mission, an experiment was conducted to study its feasibility for advanced hotspot monitoring. In addition to hotspot imaging already provided by commercial imaging systems, the identification of the variety of radioisotopes is realized thanks to the good energy resolution given by the semiconductor detectors. Three radioisotopes of 
Ba (356 keV), 
Na (511 keV) and 
Cs (662 keV) were individually imaged by applying event selection in the energy window and the -ray images was correctly overlapped by an optical picture. The detection efficiency of 1.68
10
(effective area: 1.710 cm
) and angular resolution of 3.8
were obtained by stacking five detector modules for 662 keV -ray. The higher detection efficiency required in a specific use can be achieved by stacking more detector modules.
Sakaguchi, Shinobu; Tachibana, Ikuya; Koshino, Katsuhiko; Shirozu, Hidetomo; Shirai, Nobutoshi; Imamoto, Nobuo; Tomita, Tsuneo; Tobita, Hiroo; Yamanaka, Atsushi; Kobayashi, Daisuke; et al.
JAEA-Technology 2011-006, 24 Pages, 2011/03
JAEA-Technology-2011-006.pdf:3.07MB
In the Niigataken Chuetsu-oki Earthquake on 2007, observed earthquake motion exceeded design base at the Kashiwazaki Kariwa nuclear plant. However, there was no earthquake damage in safety important equipments to stop reactor, to cool reactor, and to contain radioactive materials. One of this reason is said that many safety margin are included in the design and the permissible value. To know more accurate safety margin, shearing force examinations for the base bolts were conducted. In examinations, delegate test-bolts were made; the test bolts were selected from heavier equipment in Tokai Reprocessing Plant. In this report, the shearing strength obtained from the examinations shows more accurate safety margin.
Kawamura, Hideki*; Ando, Kenichi*; Noda, Masaru*; Tanaka, Tatsuya*; Matsuda, Takeshi*; Fujii, Haruhiko*; Hashimoto, Shuji*; Ueda, Tadashi*; Matsui, Hiroya; Takeuchi, Shinji; et al.
JAEA-Technology 2009-081, 182 Pages, 2010/03
JAEA-Technology-2009-081.pdf:28.89MB
Grouting has practical importance for the reduction of groundwater inflow into excavations during construction of underground facilities. Considering the performance assessment of a radioactive waste repository, the performance of the engineered barrier system could be adversely affected by a high pH plume generated from grout. Therefore, a quantitative estimation of the effectiveness of grouting and grout material is essential. This study has been performed in the Mizunami URL being excavated in crystalline rock as a part of the Project for Grouting Technology Development for the Radioactive Waste Repository funded by METI, Japan. The aims were to evaluate the applicability of existing grouting technology and to develop methodology to determine the distribution of grout and change in hydraulic properties of the grouted rock volume. The target rock is the volume of rock around a planned refuge niche where the pre-excavation grouting was performed at 200-m depth from ground surface. After excavation of the refuge niche, ten boreholes were drilled and different kinds of investigations were carried out during and after drilling. The results were integrated and groundwater flow analysis of pre and post excavation grouting conditions were carried out to estimate quantitatively the effect of pre-excavation grouting. The results suggest that current pre-excavation grouting technology is effective for reduction of groundwater inflow into excavations and that hydraulic conductivity of the surrounding rock can be reduced by more than one order of magnitude.
Matsui, Hiroya; Tanaka, Tatsuya*; Fujii, Haruhiko*; Takeuchi, Shinji; Iyatomi, Yosuke; Sugihara, Kozo
Dai-38-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.131 - 136, 2009/01
Grouting is practically important to reduce groundwater inflow into a cavern for construction of underground facilities. Studies on the grouting performance were carried out in Mizunami URL excavated in crystalline rock. The aims of these studies are to evaluate the applicability of existing grouting technology and to develop the methodology for the estimation of grouting performance, e.g., the extension of grout, hydraulic property change. The results suggests that the existing grouting technology is effective to reduce groundwater inflow into drifts and the hydraulic conductivity in the surrounding rock may decrease by two orders of magnitude before grouting.
Tanaka, Tatsuya*; Matsui, Hiroya; Hashimoto, Shuji*; Ando, Kenichi*; Takeuchi, Shinji; Saegusa, Hiromitsu
Dai-38-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.143 - 148, 2009/01
This study aims to establish techniques for grouting, and evaluation of the effects of grouting on the geological environment, to be applied in the field of high level radioactive waste disposal in the deep underground. A block-scale hydrogeological model has been generated using discrete fracture networks based on data obtained from the short-borehole investigation campaign performed at the research tunnel around which grouting has been carried out. The grouting performance in terms of reducing the water inflow rate was evaluated by groundwater flow simulation. Lessons learned applicable to future studies of in-situ testing have been addressed.
Ando, Kenichi*; Takeuchi, Shinji; Matsui, Hiroya; Tanaka, Tatsuya*; Hashimoto, Shuji*; Fujii, Haruhiko*
Dai-38-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.137 - 142, 2009/01
Evaluation of the effect of grouting on the geological environment is important for quality control of the design and management of the construction of underground facilities for high level radioactive waste disposal. Lugeon test has been commonly used to check the hydraulic characteristics around borehole whether or not to inject grout in Japan. The aim of this study is to develop a hydraulic test which can be applied to obtain hydraulic conductivities of low permeable rockmass (e.g. 10
to 10
m/s) during grouting. The proposed hydraulic test with the test sequence of water injection and pressure recovery has been carried out in Mizunami URL excavated in crystalline rock. The developed type curve matching methodologies have been applied to evaluate hydraulic conductivity in-situ in a simple manner. Lessons learned for future application for grouting have been addressed.
Yamaguchi, Hiroyasu*; Shimizu, Akemi*; Hase, Yoshihiro; Degi, Konosuke*; Tanaka, Atsushi; Morishita, Toshikazu*
Euphytica, 165(1), p.97 - 103, 2009/01
Times Cited Count：29 Percentile：76.38(Agronomy)We compared the effects of ion-beam and -ray irradiation on mutation induction in axillary buds of chrysanthemum, and analyzed the chimeric structure of the resulting mutants. Axillary buds were irradiated with carbon ions (mean LET 122 keV/m), helium ions (9 keV/m), and rays. The lower five nodes of shoots elongating from the irradiated buds were cut one by one, and new shoots were allowed to grow. This procedure was repeated twice and flower color mutation was investigated. Chimeric structure was analyzed by comparing the flower color of mutants to that of plants regenerated from the roots. All the flower color mutants induced with rays were periclinal chimeras. In contrast, some mutants obtained with ion beams had the same flower color as that of the plants derived from the roots. This suggests that they were solid mutants, where both LI and LIII tissues were derived from the same mutated cell.
-rays; Guineagrass and sorghumNakagawa, Hitoshi*; Inafuku, Masashi*; Kusaba, Makoto*; Yamaguchi, Hiroyasu*; Morishita, Toshikazu*; Morita, Ryohei*; Nishimura, Minoru*; Hoeman, S.*; Yokota, Yuichiro; Hase, Yoshihiro; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 72, 2008/03
no abstracts in English
Matsui, Hiroya; Kurikami, Hiroshi; Kunimaru, Takanori; Morioka, Hiroshi; Hatanaka, Koichiro
Rock Mechanics; Meeting Society's Challenges and Demands, p.1193 - 1201, 2007/05
JAEA is developing two off-site underground research laboratory projects: one in sedimentary rock (Horonobe, Hokkaido) and the other in crystalline rock (Mizunami, Gifu) in Japan. Horonobe's URL project consists of three major phases: (1) surface-based investigation (Phase I); (2) construction (Phase II); and, (3) operation (Phase III). At present, Phase II has been started. In parallel, predictions of potential changes in the geological environment prevailing around the URL are in progress. This paper mainly gives an overview of the technical aspects covered by Phase I as well as presents the design for the URL. Future plans after Phase II are briefly introduced as well.
rayMorita, Ryohei*; Morishita, Toshikazu*; Nakagawa, Hitoshi*; Nishimura, Minoru*; Yamaguchi, Hiroyasu*; Yokota, Yuichiro; Hase, Yoshihiro; Tanaka, Atsushi
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 78, 2007/02
no abstracts in English
Seno, Shoji*; Toida, Masaru*; Kobayashi, Ichizo*; Tanaka, Mayumi*; Matsui, Hiroya; Kunimaru, Takanori; Kurikami, Hiroshi
Nihon Chikasui Gakkai 2006-Nen Shuki Koenkai Koen Yoshi, p.310 - 315, 2006/10
no abstracts in English
Shirato, Nobuaki*; Matsui, Hiroya; Morioka, Hiroshi; Hatanaka, Koichiro; Takeuchi, Ryuji; Hatakeyama, Nobuya; Ohara, Hidefumi; Nakajima, Takahiro; Kunitomo, Takahiro
JNC TN5440 2005-001, 412 Pages, 2005/06
JNC-TN5440-2005-001.pdf:20.87MB
We held Horonobe technical review meeting 4 times a year. The first meeting is for the plan of Horonobe underground research laboratory and others. The secound meeting is for geology of Horonobe area and modeling study and data acquisition for safety assessment methodology and others. The third meeting is for ventilation network analyses on URL plan. The fourth meeting is for the remote monitoring system using ACROSS. This report is records of these meetings.
Yamazaki, Shinichi; Matsui, Hiroya; Hama, Katsuhiro; Morioka, Hiroshi; Hatanaka, Koichiro; Fukushima, Tatsuo; Seya, Masami
JNC TN5400 2004-005, 181 Pages, 2004/12
JNC-TN5400-2004-005.pdf:49.9MBJNC-TN5400-2004-005(errata).pdf:0.08MB
This report includes the records for the international workshop on Hornobe Underground Research Laboratory Project. Abstracts, Slides for Presentation, and so on.
Yamazaki, Shinichi; Matsui, Hiroya; Hama, Katsuhiro; Morioka, Hiroshi; Hatanaka, Koichiro; Fukushima, Tatsuo
JNC TN5400 2004-004, 41 Pages, 2004/10
JNC-TN5400-2004-004.pdf:4.66MB
Japan Nuclear Cycle Development Institute (JNC) is pursuing two underground research laboratory (URL) projects to conduct a systematic research on geological disposal of high level radioactive wastes. The Tono Geoscience Center (TGC) has been carrying out research and development in crystalline rocks at Mizunami in central Japan and the Horonobe Underground Research Center in sedimentary rocks at Horonobe in northern Japan. Both projects are nearing termination of the first phase of surface-based investigation and is about to move on to the next phase of actually constructing the facilities underground. To mark this transition of phases, an international conference is organized to promote domestic and international recognition for the significance of constructing the URLs by disseminating research findings to a broad range of researchers and specialists from within and outside Japan as well as to the local community.
Yb
Lu for spectroscopy of proton-proton and other sub-MeV solar neutrinosFujiwara, Mamoru; Akimune, Hidetoshi*; Van den Berg, A. M.*; Cribier, M.*; Daito, Izuru*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujita, Yoshitaka*; Goodman, C. D.*; Hara, Keigo*; et al.
Physical Review Letters, 85(21), p.4442 - 4445, 2000/11
Times Cited Count：24 Percentile：73.97(Physics, Multidisciplinary)no abstracts in English
