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Nakayoshi, Akira; Kitawaki, Shinichi; Fukushima, Mineo; Kurata, Masaki*; Yahagi, Noboru*
no journal, ,
no abstracts in English
Takano, Masato; Kojima, Hiroshi; Tanaka, Kenji; Kobayashi, Kentaro; Tsukamoto, Ryosuke*
no journal, ,
no abstracts in English
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Kobayashi, Kentaro; Sasaki, Tadashi*
no journal, ,
In Nuclear Fuel Reprocessing Plant, it is necessary to dispose of a large amount of low level radioactive effluent containing nitrate as a major ingredient, safely and economically. Therefore, engineering developments concerning a cement based encapsulation process have been carried out in JAEA. From the view point of disposal cost decrease, a low level radioactive effluent is passed through the nuclide separation process before cementation to concentrate the radioactivity into the minimum volume for conditioning and disposal. Two kinds of effluents are generated as a result of the nuclide separation; A nitrate effluent of which the principal ingredient is nitrate with a comparatively low radiation level, and; A slurry effluent including several kinds of salts with a comparatively high radiation level. Non-radioactive stimulants were prepared for each of these waste streams, and used in encapsulation trials to investigate special slag cement, on a beaker scale and full scale(200-litres). Furthermore, JAEA has carried out hazardous material judgment for cement products and leaching test of the cement products which encapsulated actual effluent. I will report that result of there development trials.
Watanabe, So; Sano, Yuichi; Koma, Yoshikazu; Goto, Ichiro
no journal, ,
no abstracts in English
Yamamoto, Masahiko; Surugaya, Naoki; Taguchi, Shigeo; Watahiki, Masaru; Yoshimura, Kazuhisa*
no journal, ,
no abstracts in English
Nagatani, Taketeru
no journal, ,
Japan Atomic Energy Agency (JAEA) has developed the Epithermal Neutron Multiplicity Counter (ENMC) in cooperation with Los Alamos National Laboratory. The ENMC is the nondestructive assay (NDA) system that measures the quantity of plutonium mass with a short time and high-precision in comparison with the existing system by measuring the epithermal neutron in addition to the thermal neutron. JAEA performed the accuracy evaluation test to evaluate the possibility of high-precision measurement as DA level. As the results of this test, it was found that measurement accuracy of the ENMC will be able to improve to approximation 0.5%.
Shinohara, Masanori
no journal, ,
no abstracts in English
Tanaka, Nobuyuki; Asano, Masaharu; Onuki, Kaoru; Maekawa, Yasunari
no journal, ,
For the improvement of the efficiency of thermochemical water-splitting IS process, it is necessary to pre-concentrate the HIx solution to over-azeotropic concentration. In JAEA, the development of the radiation grafted polymer electrolyte membrane was pushed forward and the result for fuel cells was gained. As the result of the application to HI concentration, compared with the conventional membrane, the cell voltage was lower 30% and the consumption energy was reduced 25% at 100
C. Therefore, the effect of energy reduction was accepted in the high temperature environment as well.
irradiationKomeno, Akira; Kato, Masato; Morimoto, Kyoichi; Kashimura, Motoaki; Sugata, Hiromasa*; Shibata, Katsuya*; Tamura, Tetsuya*; Uno, Hiroki*
no journal, ,
no abstracts in English
absorbed dose ratesYoshida, Tadayoshi
no journal, ,
no abstracts in English
Nakamichi, Shinya; Kato, Masato; Sunaoshi, Takeo*; Morimoto, Kyoichi; Kashimura, Motoaki; Kihara, Yoshiyuki
no journal, ,
no abstracts in English
Aoyama, Yoshio; Sakakibara, Tetsuro; Yamaguchi, Hiromi; Sasaki, Naoto*; Taniguchi, Shoji*; Fujita, Michiru*; Suzuki, Hiroshi*
no journal, ,
no abstracts in English
Seki, Yohji; Akiba, Masato; Enoeda, Mikio; Suzuki, Satoshi; Nishi, Hiroshi; Ezato, Koichiro; Yokoyama, Kenji; Tanigawa, Hisashi; Mori, Seiji; Tanzawa, Sadamitsu; et al.
no journal, ,
The one-dimensional nuclear and thermal analyses on Test Blanket Module (TBM) in ITER have been performed for emphasizing on optimized layer structures of a ceramic tritium breeder (
) and a beryllium neutron multiplier 
. The numerical simulation of the helium purge gas in the breeder pebble bed also has been performed. The main results of our study are as follows: (1) In the case of the single packing for multiplier pebble bed, The tritium product ratio of single packing is comparable in magnitude to that of binary packing by setting the two layers of Be behind a layer of . (2) The high concentration of the tritium stays near the first wall and membrane panel because of the effect of insufficient convective diffusion in low Reynolds number. This work contributes to the designs of the TBM and demonstration blanket.
Obara, Satoshi; Otsuka, Satoshi; Wakai, Takashi; Inoue, Masaki; Asayama, Tai; Suzuki, Junichi; Onuma, Masato*
no journal, ,
no abstracts in English
Ueta, Shohei
no journal, ,
Japan Atomic Energy Agency (JAEA) is developing the zirconium carbide (ZrC) coated fuel particle which has better refractoriness and chemical stability than the conventional silicon carbide (SiC) coated fuel particle. In the present study, ZrC coating tests were carried out by the enlarged 200g-scale ZrC coater comparing with the previous study. Finally, the stoichiometric ZrC layer was successfully fabricated by obtaining relationships between properties of ZrC, coating temperature and batch size through coating tests. In addition, not only inspection methods for coating thickness and density, but also treatment technique to remove pyrocarbon (PyC) layer were developed in order to evaluate the quality of the ZrC coated fuel particle. Present R&D will contribute to the practicability of the ZrC coated fuel particle as a fuel for the advanced high temperature gas cooled reactor such as the Very High Temperature Reactor (VHTR).
Shimojo, Kojiro; Yaita, Tsuyoshi; Suzuki, Shinichi; Naganawa, Hirochika
no journal, ,
no abstracts in English