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Kawatsuma, Shinji; Nakai, Koji; Suzuki, Yoshiharu; Kase, Takeshi
QST-M-2; QST Takasaki Annual Report 2015, P. 81, 2017/03
Radiation Tolerance of semiconductor components on the shelf, utilized on the robots for emergency response or decommissioning in nuclear facilities, should be estimated. Just after the Fukushima Daiichi NPPs accidents occurred, a guideline, of irradiation tolerance estimation and management method of semiconductor components on the shelf, was tried to be made based on the old database developed in the course of Bilateral Servo Manipulator under the high radiation and high contamination environments. The estimation was conservative, because the data in the database were old and mainly based on the test results of silicon semiconductors. Ga-As Semiconductors are coming major recently, and expected to be higher radiation tolerance. For those reason, present semiconductor devices have irradiated and the irradiation tolerance have estimated.
Arai, Yoichi; Ogino, Hideki; Takeuchi, Masayuki; Kase, Takeshi; Nakajima, Yasuo
Proceedings in Radiochemistry, 1(1), p.71 - 74, 2011/09
Solvent cleanup method using activated alumina was discussed in this study. This method was one of candidate to remove TBP/
-dodecane degradation products. The degradation sample of 30% TBP/-dodecane was prepared by irradiation (1.6 MGy) using 
Co 
-source. The absorbed dose for sample was almost 1.6 MGy. The degradation products were qualitatively analyzed by gas chromatography-mass spectrometer (GC-MS). After the irradiation, solvent cleanup was performed by activated alumina and the cleanup using alumina was examined by phase separation test with 3M HNO
. As the result, it was found that hexane and long-chain alcohols were mainly generated as the n-dodecane degradation products by irradiation, and almost 70% of the TBP/-dodecane degradation products were removed and the phase separation performance were improved by the cleanup using activated alumina.
Takeuchi, Masayuki; Ogino, Hideki; Nakabayashi, Hiroki; Arai, Yoichi; Washiya, Tadahiro; Kase, Takeshi; Nakajima, Yasuo
Journal of Nuclear Science and Technology, 46(3), p.217 - 225, 2009/03
Times Cited Count：11 Percentile：59.85(Nuclear Science & Technology)Takeuchi, Masayuki; Arai, Yoichi; Kase, Takeshi; Koizumi, Tsutomu
Proceedings of International Symposium on EcoTopia Science 2007 (ISETS '07) (CD-ROM), p.1084 - 1088, 2007/11
Pyrochemical reprocessing methods using molten salt for spent nuclear fuel have been studied in the world, because of advantage over the nuclear weapons proliferation and cost benefit. However, electrowinning process, which is one of the processes in pyrochemical reprocessing method, includes severe corrosion environment. In this study, the efficacy of cold crucible in electrowinning process was experimentally discussed. We carried out the corrosion test of several metals in molten 2CsCl-NaCl with corrosive gases at 923 K to investigate the relationship between material temperature controlled by air cool and corrosion rate. As results, the corrosion rate of hastelloy alloy was less than 0.1 mm/y by cooling the material surface at 473 K and corresponds to 1/1000 of that at 923 K. In such way, the cold crucible gives the extreme improvement of corrosion, and this result gave promising prospect to solve the corrosion problem in electrowinning process.
Okamura, Nobuo; Takeuchi, Masayuki; Ogino, Hideki; Kase, Takeshi; Koizumi, Tsutomu
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.1070 - 1075, 2007/09
no abstracts in English
Tomita, Yutaka; Morihira, Masayuki; Tamaki, Yoshihisa*; Nishimura, Kazuhisa*; Shoji, Shuichi*; Kihara, Yoshiyuki; Kase, Takeshi; Koizumi, Tsutomu
JAEA-Research 2006-088, 95 Pages, 2007/01
JAEA-Research-2006-088.pdf:23.02MB
JAEA has developed sphere-pac fuels in the feasibility study on commercialized FBR cycle systems as one of the candidates for low decontamination TRU fuels. Optimization of the fabrication condition for coarse spheres, development of an improved external gelation process, and examination of peculiar problems for the low decontamination fuel were carried out in Phase II. The results are shown as follows. (1) Fabrication condition of coarse spheres was optimized. (2) Feasibility of the improved external gelation process was confirmed. (3) Rare earth elements did not bring any problem for the characteristic of spheres and fabrication condition. (4) Radiation resistant data of the feed solution was acquired. Results of tests show the feasibility of the external gelation process for the low decontamination TRU fuel microsphere fabrication.
Nakagiri, Toshio; Kase, Takeshi; Kato, Shoichi; Aoto, Kazumi
JSME International Journal, Series B, 49(2), p.302 - 308, 2006/05
A new thermo-chemical and electrolytic hybrid hydrogen production system in lower temperature range is newly proposed by the Japan Atomic Energy Agency (JAEA) to realize the hydrogen production from water by using the heat generation of sodium cooled Fast Breader Reactor (FBR). The system is based on sulfuric acid (H
SO
) synthesis and decomposition process developed earlier (Westinghouse process), and sulfur trioxide (SO) decomposition process is facilitated by electrolysis with ionic oxygen conductive solid electrolyte to reduce the operation temperature 200-300 
C lower than Westinghouse process. SO decomposition was confirmed experimentally, and theoretical thermal efficiency was evaluated. Furthermore, hydrogen production experiments to substantiate the whole process were performed. Stable hydrogen and oxygen production were observed in the experiments, and maximum duration of the experiments was about 5 hours.
Nakagiri, Toshio; Kase, Takeshi; Kato, Shoichi; Aoto, Kazumi
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 7 Pages, 2005/05
A new thermochemical and electrolytic hybrid hydrogen production system for sodium cooled FBR has been proposed and developed by JNC. SO3 splitting experiments, theoretical evaluation of thermal efficiency and hydrogen production experiments to substantiate the whole process were performed. Maximum 5 hours stable hydrogen production was obserbed in the hydrogen production experiments.
Nakagiri, Toshio; Kase, Takeshi; Kato, Shoichi; Aoto, Kazumi; Takamori, Yuji*
JNC TN9400 2005-016, 27 Pages, 2005/04
JNC-TN9400-2005-016.pdf:1.37MB
To improve the energy efficiency of the thermo-chemical and electrolytic hybrid hydrogen production system, the techniques and electrolysis condition which reduced the voltage loss of sulfurous acid solution electrolysis were surveyed and discussued. As the result of the survey and discussion, a gas diffusion type anode was effective in a reduction of voltage loss, a cathode poisoning by sulfur and a omission of SO absorption part. A membrane electrode assembly type cathode was expected to reduce a voltage loss because of the minimum distance between membrane and electrode. In the point of voltage loss reduction, a stream type cell was proper to achieve a rapid reaction material supply. It was effective for experimental apparatus with capability in 1L/h hydrogen production to adopt these techniques, because a cell, which adopted these techniques, achieved a current density of more than 100mA/cm
.
Nakagiri, Toshio; Horikiri, Morito; Kato, Shoichi; Kase, Takeshi; Aoto, Kazumi; Takamori, Yuji*; Fukasaku, Hiroshi*
JNC TN9400 2004-056, 98 Pages, 2004/09
JNC-TN9400-2004-056.pdf:5.58MB
Hydrogen production demonstration experiments from water by the thermochemical and electrolytic hybrid hydrogen production process were performed. The feasibility of this hydrogen production process was demonstrated and technical problems to operate longer uration and to develop 1Nl/h-H2 production experimental apparatus were extracted. (1) Continuous and stable hydrogen and oxygen generation by the hybrid process was measured in the four full process experiments and maximum test duration was about five hours. The generation rate of hydrogen and oxygen calculated from measured current in four full process experiments were 4.03ml/h - 5.04ml/h and 2.07ml/h - 2.78ml/h, respectively. The total amounts of generated hydrogen and oxygen in the four experiments were 35.00ml and 20.99ml. (2) Severe material corrosion was not observed for gold plated stainless steel and S03 electrolysis cell (YSZ, Pt paste electrode) which used in sulfuric acid atmosphere at about 550 deg-C, and ionic oxygen conductivity of YSZ did not decrease in the experiments. Nevertheless, corrosion of the gold plated outlet piping of S03 electrolysis cell was observed, and the corrosion by condensed sulfuric acid as suspected. (3) Technical problems to operate the present experimental apparatus for 100 hours and to develop test apparatus to generate 1Nl/h hydrogen, were extracted.
Kase, Takeshi; ; Fujita, Yuji; Ueda, Yoshinori
Saikuru Kiko Giho, (4), 27-35 Pages, 1999/00
None
Kase, Takeshi; Harada, Hideo
Nuclear Science and Engineering, 126(1), p.59 - 70, 1997/05
Times Cited Count：6 Percentile：47.96(Nuclear Science & Technology)no abstracts in English
Kase, Takeshi; Harada, Hideo; Takahashi, Takeshi
Progress in Nuclear Energy, 29(Suppl.), p.335 - 341, 1995/00
None
Harada, Hideo; Nakamura, Yuji*; Kase, Takeshi; Takahashi, Takeshi
PNC TN8410 94-123, 39 Pages, 1994/04
None
Kase, Takeshi; Harada, Hideo; Takahashi, Takeshi
Proceedings of International Symposium on Global Environment and Nuclear Energy Systems, 0 Pages, 1994/00
None
Harada, Hideo; Takahashi, Hiroshi*; Aronson, A. L.*; Kase, Takashi; Konashi, Kenji; Sasao, Nobuyuki
Fusion Technology, 24(2), p.161 - 167, 1993/09
None
Kase, Takeshi; Nakamura, Takashi*; Yamadera, Akira*; Uno, Yoshitomo*; Takada, Masashi*
PNC TY8601 93-001, 75 Pages, 1993/05
no abstracts in English
Harada, Hideo; Takahashi, Hiroshi*; Aronson, A. L.*; Konashi, Kenji; Kase, Takashi; Sasao, Nobuyuki
PSI-Proceedings 92-02, p.383 - 407, 1992/09
no abstracts in English
