Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Asami, Makoto; Watahiki, Hiromi; Oi, Takao; Shibata, Atsuhiro; Ashida, Takashi
JAEA-Data/Code 2015-020, 80 Pages, 2015/11
JAEA-Data-Code-2015-020.pdf:45.07MB
JAEA-Data-Code-2015-020-appendix(DVD-ROM).zip:602.44MB
FY2014 edition of the analysis results on contaminated water in the circulating system and on rubbles/soils of Fukushima Daiichi Nuclear Power Station (1F NPS) was compiled. This technical report shows the function of the electronic file of the FY2014 edition of the analysis results on contaminated water and on rubbles/soils and presents the user manual with example and gives the electronic file by appendix CD.
Asami, Makoto; Watahiki, Hiromi; Oi, Takao; Makino, Hitoshi; Shibata, Atsuhiro; Kameo, Yutaka; Meguro, Yoshihiro; Ashida, Takashi
JAEA-Data/Code 2014-016, 37 Pages, 2014/09
JAEA-Data-Code-2014-016.pdf:37.04MBJAEA-Data-Code-2014-016-appendix(CD-ROM).zip:60.46MB
A database on the analyses of samples obtained from contaminated water in the circulating system of Fukushima Daiichi Nuclear Power Station was built. This database contains the analyses of 25 samples of JAEA and 313 samples of TEPCO which have been published in FY 2011 to FY 2013. Also, as well as the analyses on contaminated water, the information on the stored and treated amount in accumulated water and the amount of produced waste, which has been published by TEPCO and which might be required in order to estimate the inventory of secondary waste (sludge, used vessels) generated by treatment of contaminated water are contained in this database. This technical report shows the function of this database and user manual with example and presents the FY2013 edition of database by appendix CD.
Suguro, Toshiyasu; Nishikawa, Yoshiaki*; Watahiki, Takashi*; Kagawa, Akio
JAEA-Technology 2013-023, 22 Pages, 2013/10
JAEA-Technology-2013-023.pdf:2.41MB
For safety assessment of TRU waste disposal, solubility of plutonium was investigated under hardened cement paste porewater condition. Polycarboxylic acid compound, which have the possibility to be used for the TRU waste disposal, was selected as the cement admixture for the experiment. Initial concentration of Pu was 10
M in the experiment. The porewater of hardened cement paste was obtained by squeezing out the kneading of ordinary portland cement and deionized water with the cement admixture. The porewater of hardened cement paste without cement admixture is also used for the experiment. The maximum experimental period was 154 days. The experiment was carried out at room temperature (298 
5 K) under argon atmosphere, in which oxygen concentration was lower than 1 ppm. Pu concentration in the porewater of hardened cement paste with or without the cement admixture were in the order of 10
mol/dm
after 154 days. This value is comparable to the solubility of Pu(IV) under high pH condition, suggesting that the solubility of Pu was not affected by the cement admixture in hardened cement paste.
Kitamura, Akihiro; Nakai, Koji; Namekawa, Takashi; Watahiki, Masatoshi
Nuclear Engineering and Design, 241(7), p.2614 - 2623, 2011/07
Times Cited Count：5 Percentile：38.51(Nuclear Science & Technology)We developed a remote control system to display recreated three dimensional information of workspace from measured data obtained by laser rangefinder and to operate manipulator arm remotely. In order to evaluate the effectiveness and usefulness of developed system, we implemented remote handling experiments using mock up equipment and compared the performances of remote operation conducted by the present control system with that by the usual camera based control system. Impressions of operator on the performance of each system are collected and NASA TLX tests are conducted. It was observed that the present system reduced workload stresses and reinforced visual information during remote operation.
Suguro, Toshiyasu; Nishikawa, Yoshiaki*; Watahiki, Takashi*; Kagawa, Akio; Iijima, Kazuki
JAEA-Technology 2010-048, 32 Pages, 2011/03
JAEA-Technology-2010-048.pdf:0.89MB
Cementitious materials are considered to be necessary for the construction of TRU waste repository. The cement additives are used for cements and concretes in order to provide their fluidity. Many kinds of cement additives contain organic compounds which may increase radionuclide solubility by complex formation. Therefore, it is important to obtain the solubility data with cement additives for safety assessment of TRU waste disposal. In this work, two types of cement additives, such as sodium formaldehyde acid polymer and poly carboxylic acid polymer which are expected to be applied to the TRU waste disposal system, are selected. Since the chemical condition of the repository is considered to be reducing, the authors carried out batch-type experiments of plutonium solubility under reducing (Na
SO
added as reducant) and anoxic condition ([O] 
1 ppm). Other experimental conditions are (1)initial plutonium concentration; 10 M, (2) temperature; 2985 K, (3)experimental period; 7, 14, 28 and 56 days and (4) molecular weight of cement additives; without fractionation 
5,000 and 
5,000. The plutonium concentration in the absence of the cement additives was in the order of 10 mol dm
, while, those in the presence of cement additives were two or three orders of magnitude higher. Additionally, low molecular weight fraction of cement additives brought relatively higher plutonium concentration than high molecular weight fraction.
Watahiki, Shunsuke; Saito, Takashi; Tsuchiya, Kunihiko; Ohara, Hiroshi; Iimura, Koichi
JAEA-Technology 2008-044, 42 Pages, 2008/06
JAEA-Technology-2008-044.pdf:5.43MB
This report is described for the development of nicrosil-nisil type multi-paired thermocouple which was usable at over 1000 degrees under the neutron irradiation environment. Developed nicrosil-nisil type multi-paired thermocouple has maximum 7 hot junctions in axial direction in a sheath. Though the design, trial production and out-pile tests, its productivity and electric performances were confirmed, and the production method was established.
Hanawa, Yoshio; Taguchi, Taketoshi; Tsuboi, Kazuaki; Saito, Takashi; Ishikawa, Kazuyoshi; Watahiki, Shunsuke; Tsuchiya, Kunihiko
JAEA-Technology 2008-039, 53 Pages, 2008/06
JAEA-Technology-2008-039.pdf:6.18MB
Beryllium has been utilized as a moderator and/or reflector in a number of material testing reactors. Beryllium frames and beryllium reflectors, which have been utilized as neutron reflector in Japan Materials Testing Reactor (JMTR) in JAEA, were fabricated beryllium metals of S-200F grade. Especially, it is necessary to exchange the beryllium frames every fixed period and there frames were exchanged six times up to the JMTR operation periods of 165 cycles. Therefore, preliminary irradiation test of beryllium metals was performed from 162 to 165 cycles of JMTR operations as a part of development on long life of beryllium reflectors. Two kinds of beryllium metals (S-200F and S-65C) were prepared in this test. This report is described the design study and fabrication of irradiation capsule of beryllium metals and dismount device of irradiation capsule.
Tobita, Noriyuki; Okada, Takashi; Kashiro, Kashio; Matsumoto, Masaki; Watahiki, Masatoshi; Nakata, Keiji*; Gonnokami, Kiyomi*
JNC TN8430 2004-001, 125 Pages, 2004/12
JNC-TN8430-2004-001.pdf:143.53MB
An event that a pre-filter burned on fire took place in the glove box dismantlement facility of Plutonium Production Facility, on April 21, 2003. The direct cause of this event was considered to be sparks generated by an abrasive wheel cutter, some of which reached the pre-filter and eventually burned the pre-filter. Further investigation revealed that there exist other deficiencies those of which formed indirect causes of the event, such as the wheel cutter was used without protective cover and adequate shield against sparks was not installed during the operation. To prevent similar event in the future, following corrective actions were introduced. Wheel cutter will not be used without protective cover; Incombustible pre-filter will be used; Shield will be place at the front of the pre-filter. We have conducted series of experimental tests in order to evaluate and confirm the validity of these corrective actions as well as determine the cause of the fire. This report present the results of these tests.
Watahiki, Shunsuke; Nakamichi, Masaru; Naka, Michihiro; Saito, Takashi; Ide, Hiroshi; Miyazawa, Masataka; Ishihara, Masahiro; Kawamura, Hiroshi
no journal, ,
The development of in-core remote sensing Technology is essential to aim at the realizayion of advanced irradiation examination in the new JMTR. By observing the in-core on real time and taking out nucleus and thermal information as optical information, the technology may be able to detect a very small change of the in-core, which is undetectable by the usual instrumentation. As a result, a highly accurate irradiation examination can be done. In the present study(work), the spent fuel kept in the spent fuel rack in the canal(water way) of JMTR was recorded with a video camera(visible light), and the brightness of Cherenkov radiation was evaluated from the radiation the obtained image.
Ide, Hiroshi; Ishitsuka, Etsuo; Watahiki, Shunsuke; Saito, Takashi; Inaba, Yoshitomo; Kawamura, Hiroshi
no journal, ,
no abstracts in English
Suguro, Toshiyasu; Kagawa, Akio; Nishikawa, Yoshiaki*; Watahiki, Takashi*; Mihara, Morihiro; Iijima, Kazuki
no journal, ,
no abstracts in English
