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Kihara, Shinji; Amazawa, Hiroya; Sakai, Akihiro; Nakata, Hisakazu; Kugo, Teruhiko; Matsuda, Norihiro; Oizumi, Akito; Sasamoto, Hiroshi; Mitsui, Seiichiro; Miyahara, Kaname
JAEA-Research 2013-033, 320 Pages, 2014/07
JAEA-Research-2013-033.pdf:119.17MB
JAEA performed decontamination experiments at two test sites that combined a range of buildings and different types of land use, located in Date and Minami Soma municipalities as field pilot projects in order to accumulate knowledge and data for full-scale decontamination activities performed by local governments. In the pilot projects, we established its plan using practical decontamination methods that can be easily implemented, according to decontamination targets (e.g., forests, agricultural land, residential house and roads) at each site. As a result of the decontamination, the average air dose rates were reduced to approximately one half of the values before decontamination.
Iimure, Takashi*; Hoki, Takehiro*; Hase, Yoshihiro; Nozawa, Shigeki; Narumi, Issey*; Kihara, Makoto*; Ogushi, Kensuke*
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 109, 2014/03
Konishi, Tomoya*; Nishiwaki, Nagatoshi*; Tojo, Takashi*; Ishikawa, Takuma*; Teraoka, Teruki*; Ueta, Yukiko*; Kihara, Yoshifumi*; Moritoki, Hideji*; Tono, Tatsuo*; Musashi, Mio*; et al.
Physica Status Solidi (C), 8(2), p.405 - 407, 2011/02
Times Cited Count：3 Percentile：74.76(Engineering, Electrical & Electronic)Fujishita, Hideshi*; Hayashi, Makoto*; Kanai, Takashi*; Yamada, Takahiro*; Igawa, Naoki; Kihara, Kuniaki*
Journal of Physics and Chemistry of Solids, 71(9), p.1285 - 1289, 2010/09
Times Cited Count：3 Percentile：17.12(Chemistry, Multidisciplinary)Atomic displacements are order parameters for displacive structural phase transitions. The temperature evolution of Si atomic displacement in quartz was analyzed by studying the quantum expansion of the Landau potential. The expansion was found to accurately describe the evolution of the atomic displacement over the entire temperature interval. A proportional relationship between spontaneous strain and the square of the atomic displacement was observed over the entire temperature interval.
Kato, Masato; Morimoto, Kyoichi; Kihara, Yoshiyuki; Ogasawara, Masahiro*; Tamura, Tetsuya*; Uno, Hiroki*; Sunaoshi, Takeo*
JNC TN8400 2004-022, 44 Pages, 2005/03
JNC-TN8400-2004-022.pdf:5.43MB
Japan Nuclear Development Institute has developed homogeneous mixed oxide fuel containing minor actinide as a fuel of an advanced fast reactor. Study on the sintering behavior of the fuel was carried out and the heat treatment technique for preparing homogeneous low O/M fuel had been developed. In this report, oxygen potential was measured and phase relation was evaluated, which are needed essentially for developing the new type fuel.Oxygen potential of (Npsub0.02Amsub0.02Pusub0.3Usub0.66)Osub2-X was measured by gas equilibrium method as a function of temperature and O/M ratio. The MOX with MA has slightly higher oxygen potential as compared with that of MOX without MA. And the model of oxygen potential was derived from the measurement results based on lattice defect theory.In samples with low O/M ratio, two fcc phases were observed at room temperature. The temperature of the phase separation was measured and it is observed that the addition of MA have the effect to be decreased the phase separation temperature. In the MOX containing MA and Nd simulated a low decontaminated fuel, the Pu-Am-Nd oxides were precipitated by decreasing O/M ratio in less than 1.96.
Nishimura, Kazuhisa; Shoji, Shuichi*; *; Sato, Seiichi*; ; Endo, Hideo
JNC TN8430 2001-005, 64 Pages, 2001/09
The external gelation process is one of the candidates of MOX particle fuel fabrication for advanced recycle system. It was necessary to perform preliminary fuel fabrication with uranium before starting MOX tests. As the result of the preliminary examination, Basics conditions of the fabrication were obtained: (1)Optimized uranyl nitrate solution and PVA solution, as raw materials were prepared. (2)The frequency of vibration and the amount of flow were obtained with optimized broth (mixture) in the vibration dropping process. (3)The influence of composition of broth and concentration of ammonia solution on gelation process was obtained. (4)Impurities after aging, washing and drying spHerical gel were surveyed, (5)The spherical gel were calcined to oxide particles and the particles were characterized by TG-DTA, therefore it is certain that outlook on the sintered particles as final products is very clear. On the top of that, there were no fatal technicalities of the external gelation process through material balance and a diameter dispersion of spherical gel and oxide particles. It is necessary to perform uranium examination to solve some new problems, for instant, surface crack of spherical gel. Although almost of all the preparations are completed and fabrication examination of MOX particles with vibration dropping equipment are ready for starting.
Todokoro, Akio; Watahiki, Masatoshi; Kihara, Yoshiyuki; Ishii, Yasuhiko*; Ogasawara, Masahiro*; Otaka, Akihiro*
PNC TN8410 96-238, 86 Pages, 1996/08
None
Todokoro, Akio; Kihara, Yoshiyuki; Watahiki, Masatoshi; Ogasawara, Masahiro*; Otaka, Akihiro*
PNC TN8410 94-403, 30 Pages, 1994/11
None
Hayashi, Makoto*; Kanai, Takashi*; Yamada, Takahiro*; Fujishita, Hideshi*; Igawa, Naoki; Kihara, Kuniaki*
no journal, ,
While the temperature change of the static order paramaters, such as an atom displacement and lattice destortion around the phase transition temperature is exlained by the classical Landau theory, the tempereture dependence of those parameters below the transition temperature was predicted by Salje. In this report, temperature dependence of strucural parameters of quartz was measured using the nuetron powder diffraction and analyzed by the Rietveld method to confirm the theory predicted by Salje. The quantitative analysis of present works gave a good agreement with the theory.
Hayashi, Makoto*; Fujishita, Hideshi*; Kanai, Takashi*; Yamada, Takahiro*; Igawa, Naoki; Kihara, Kuniaki*
no journal, ,
A phenomenological theory describes the temperature dependence of the order parameter Q, which is atomic shift in displacement structural phase transition and of strain e, which is coupled to Q, near a phase transition. Recently, Romero and Salje showed the strain obeys the quantum phenomenological theory below the temperature of the displacement structural phase transition. However, direct evaluation of the quantum phenomenological theory by measuring the order parameters in entire temperature is required to verify the effectiveness of the theory. We carried out the structural analysis of quartz by neutron powder diffraction in the temperature range of 10-250K. We found that the strain was in proportion to the squares of the displacement of the Si atom along the a-axis in the present temperature range. The effectiveness of the theory was directly verified by the atomic displacement.
Morimoto, Kyoichi; Kato, Masato; Kihara, Yoshiyuki; Ogasawara, Masahiro*
no journal, ,
The Pu-content, O/M ratio and density of MOX fuel of fast reactors are different depending on specifications of fuel. In addition, MOX fuel containing minor actinides has become a candidate for a future nuclear fuel cycle, because it has high proliferation resistance and can reduce environmental burdens by decreasing the amount of MAs in high level radioactive waste. From these points of view, a wide variety of fuel form should be considered on the development of fast reactor fuel. Thermal conductivity of nuclear fuel is one of the most important physical properties for fuel design and performance analysis of fuel rod. In our laboratory, the thermal conductivity measurement has been carried out by using MOX specimens which prepared under various conditions. In this presentation, the various measurement data and the evaluation results of thermal conductivities obtained in our laboratory will be introduced.
Hoki, Takehiro*; Iimure, Takashi*; Hase, Yoshihiro; Nozawa, Shigeki*; Narumi, Issey*; Kihara, Makoto*; Ogushi, Kensuke*
no journal, ,
no abstracts in English
