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Sato, Takeshi; Otake, Yoshinao*; Yamada, Koji*
no journal, ,
no abstracts in English
Yamano, Hidemasa; Tobita, Yoshiharu
no journal, ,
Numerical analyses were performed with SIMMER-III to provide boundary conditions for the integral verification of the COMPASS code with in-pile and out-of-pile tests investigating key phenomena relevant to CDA analyses of fast reactors.
Niwa, Hajime; Kurisaka, Kenichi; Sato, Ikken; Tobita, Yoshiharu; Kamiyama, Kenji; Yamano, Hidemasa; Miyahara, Shinya; Ohno, Shuji; Seino, Hiroshi; Ishikawa, Hiroyasu; et al.
no journal, ,
In order to develop the core damage evaluation technology (level 2 PSA) for sodium-cooled fast reactors, we develop the new analysis codes of post accident material relocation phase and of ex-vessel events, and we develop the technical bases that is necessary for level 2 PSA. In this presentation, summary and scope of the entire study is introduced as a part of the 4 series presentations.
Kugo, Teruhiko; Mori, Takamasa; Takeda, Toshikazu*
no journal, ,
Extended bias factor method is proposed for improvement of the prediction accuracy of neutronic characteristics of a nuclear energy system. The present method utilizes a number of experimental results and produces a semi-fictitious experimental value by a product of exponentiated experimental values. A bias factor is defined a ratio of the product of exponentiated experimental values to a product of exponentiated calculation values correspoding to the experimental values. By multiplying the bias factor to a design calculation value, it is corrected into a design prediction value. Exponents are determined to minimize a variance of the design prediction value.
Kugo, Teruhiko; Ando, Masaki; Kojima, Kensuke; Mori, Takamasa; Nakano, Yoshihiro; Okajima, Shigeaki; Kitada, Takanori*; Takeda, Toshikazu*
no journal, ,
Extended bias factor method is applied for the evaluation of prediction accuracy for neutronic characteristics of light water breeding reactor with use of FCA experiments. From results of the application, it is demonstrated that extended bias factor method is very useful for improvement of the prediction accuracy and it has a possibility to complement a full scale mockup experiment by using benchmark experiments and also has a possibility to be superior to the conventional method with use of a full scale mockup experimental result including a large experimental error.
Matsumoto, Kazuhiro*; Tanai, Kenji
no journal, ,
The bentonite will be resaturated and swelled gradually after repository closure, not only will any gaps within the bentonite sealed, but the bentonite may also be excluded into fractures in the surrounding rock, diverting a part of the water flow away from the repository. However, if loss of bentonite into fractures due to extrusion is too pronounced, then the decrease in density of the bentonite within the repository may lead to reduce its favourable properties. In this study, the extrusion behavior of bentonite into the artificial fracture of the acrylic cell was investigated in consideration of flow velocity, aperture and dry density of bentonite specimen until present day. In future, experiments will be carried out to clarify the realistic behavior of extrusion phenomenon in consideration of roughness of fracture. This paper present existing results and future plan of test.
Arai, Yoichi; Ogino, Hideki; Takeuchi, Masayuki; Kase, Takeshi; Koizumi, Tsutomu
no journal, ,
no abstracts in English
Amamoto, Ippei; Kofuji, Hirohide; Myochin, Munetaka; Terai, Takayuki*
no journal, ,
no abstracts in English
Ohashi, Yusuke
no journal, ,
We propose ways to use ionic liquid as reaction media in order to separate uranium and to recover uranium from contaminated materials that is generated from nuclear fuel institutions. By using BMICl and eutectic mixtures of choline chloride-urea we did decontamination tests of waste NaF adsorption materials and metal wastes. We confirmed the solubility of uranium included in NaF into ionic liquids. The decontamination effect of ionic liquids to metal wastes were also confirmed. As a result it was confirmed that 86% of uranium included in NaF is soluble in BMICl after 3 hours soaking. 64% of uranium included in NaF was soluble in eutectic mixtures of choline chloride-urea under the same condition. On the other hand, after we have soaked contaminated metal materials into BMICl for 3 hours, the density of surface radioactivity became lower than 1/10 of levels at which we can bring it out from restricted areas.
masking agentsTakeuchi, Masayuki; Koizumi, Tsutomu; Hoshino, Kuniyoshi*; Kawamura, Fumio*
no journal, ,
no abstracts in English
Shimoda, Hiroshi*; Ishii, Hirotake*; Sekiyama, Tomoki*; Bian, Z.*; Izumi, Masanori; Morishita, Yoshitsugu
no journal, ,
This study aims at developing an augmented reality system to support maintenance work of nuclear power plants. An accurate and wide-range tracking method is required as a key technology in order to realize the system. In this study, a new tracking method using multi-camera and gyro sensor has been developed in order to enlarge the area where the tracking is available with limited number of markers. Experimental evaluation result shows that the area where the developed method can cover is about 3 times larger than the method using single camera.
Ishii, Hirotake*; Shimoda, Hiroshi*; Bian, Z.*; Izumi, Masanori; Morishita, Yoshitsugu
no journal, ,
Improvement of tracking accuracy is an important issue when applying augmented reality to nuclear power plant fieldwork. Tracking accuracy depends highly on the marker arrangement when employing a tracking method using a camera and markers. Tracking accuracy becomes low if markers are pasted arbitrarily only on places that are easy to paste them onto. For those reasons, this study develops a marker arrangement optimization algorithm based on genetic algorithms. Tracking error caused by finite camera resolution is considered particularly in this study. A wheel tracking error computation method is developed to compute the tracking error from the marker arrangement. A genetic algorithm is adopted for obtaining higher tracking accuracy from an initial pool of marker arrangements using wheel tracking error computation as a fitness function. Trial results show that the tracking accuracy can be improved markedly by applying the marker arrangement optimization algorithm.
Fukushima, Mineo; Myochin, Munetaka; Mizuguchi, Koji*
no journal, ,
no abstracts in English
Oki, Koichi; Omori, Koji; Ishibashi, Yuzo; Muto, Katsumi; Sukegawa, Yasuhiro*; Suzuki, Satoshi*
no journal, ,
no abstracts in English
Chiba, Go; Okumura, Keisuke
no journal, ,
Integral test of nuclear data of minor actinide, Cm-242, Np-237, Pu-238 and Pu-242, was carried out. The target energy range of this test is fission source range. This test suggests that (1) JENDL-3.3 overpredicts 
of reactor cores which have strong sensitivity to Pu-242 cross sections, and that (2) All the data files may underpredict a contribution of Np-237 to of reactor cores.
Kojima, Kensuke; Kugo, Teruhiko; Ando, Masaki; Okajima, Shigeaki; Mori, Takamasa
no journal, ,
Uncertainty in FCA experimental analysis due to variations in plate weight and in isotope ratio are evaluated. In the present study, uncertainty in atomic number of the whole core caused by the variation in plate weight and that in isotope ratio is considered and uncertainty in uniform placement of fuel plate with the same weight in stead of random placement of the fuel plates with the various plate weights is also considered. The uncertainty due to the uniform placement of the fuel plates is the greatest. This is caused by the greatest variance in the plate weight of the whole core with assumption of full correlations between plate weights.
Kodama, Takashi*; Nakano, Masamichi*; Matsuoka, Shingo*; Matsuura, Chihiro*; Ito, Yasuo*; Kurosu, Katsuya*; Shiraishi, Hirotsugu; Katsumura, Yosuke*
no journal, ,
It has been known that although a considerable amount of hydrogen is produced radiolytically in the high level liquid waste, only small part is emitted into the gas phase when the liquid depth is large. We report here the results of an experimental study which shows that the liquid-depth effect is caused not by the reaction between hydrogen and radicals, as has been previously suggested, but by Pd-catalyzed reaction between hydrogen and nitric acid. The method for evaluating the magnitute of the effect is also proposed.
Ishii, Tetsuya; Yoshimochi, Hiroshi; Tanaka, Kenya
no journal, ,
To investigate the fabrication method of Am-containing Oxide Fuels with metallic particles, for improvement of fuel thermo chemical properties, fabrication tests of simulated fuels using hot press sintering method were done. It can be concluded from the results that the Am-containing Oxide Fuels with metallic particles would be fabricated well by hot press sintering method.
Uwaba, Tomoyuki; Ito, Masahiro*
no journal, ,
The bundle-duct interaction (BDI) occurs in a highly irradiated wire-wrapped fast breeder reactor (FBR) fuel subassembliy and probably limits the life time of the subassembly in achieving high burn up conditions. For the purpose of evaluating bundle deformation in BDI condition, the BAMBOO calculation code has been developed. We improved the BAMBOO code so that it could analyze the bundle deformation affected by the pin-wire mechanical interaction due to the tension of the wire, by incorpolating the analysis model that predicted a single pin-wire mechanical interaction deformation into the BAMBOO. We also performed the test analysis of the improved code on a typical 169 pin bundle model, to see how the pin-wire interaction affected the whole bundle deformation behavior. The result of the analysis showed that because the tension of the wire rapidly decreased by irradiation creep, the pin-wire interaction did not significantly affect the initial pin-to-duct contact unless the tension became tighter by the difference in swelling property between the fuel cladding and the wire.
Koiso, Keiichi; Matsuyama, Yoshihiko; Umeda, Eiji; Ichitsubo, Koji; Toyoda, Yoshihiro
no journal, ,
no abstracts in English