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Nakayama, Takuya; Kawato, Yoshimi; Osugi, Takeshi; Shimazaki, Takejiro; Hanada, Keiji; Suzuki, Shinji; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro
JAEA-Technology 2014-046, 56 Pages, 2015/03
The combustible and flame-retardant radioactive wastes generated as a result of the research activities in Japan Atomic Energy Agency (JAEA) are incinerating to reduce their volume. The incinerated ash is planned to be solidified using cement for disposal. Since the properties of ashes generated in each institute of JAEA are varied with the type of incinerator and the wastes to be incinerated, it is necessary to do fundamental solidification tests in each institute to decide operating conditions of the planning cement solidification facility. It is important to standardize evaluating methods of cement and solidified waste because some characters depend on measuring method. This user's guide have been prepared how to decide the cement solidifying conditions of ash to design the cement solidification facility in JAEA. Requirements on the regulations of solidified radioactive waste have been examined and seven technical criteria, e.g. compressive strength, fluidity, have been selected as characters to be evaluated. Some empirical notes about selection of cement, admixtures, procedure on making a test piece, evaluation of expanding, compressive strength, solubility have been described. The strategy of tests and tips for finding optimized solidification condition has been summarized. Finally the example of optimized conditions satisfied the requirements and some problems to be solved have been described.
Nakayama, Takuya; Suzuki, Shinji; Hanada, Keiji; Tomioka, Osamu; Sato, Junya; Irisawa, Keita; Kato, Jun; Kawato, Yoshimi; Meguro, Yoshihiro
Proceedings of 2nd International Symposium on Cement-based Materials for Nuclear Wastes (NUWCEM 2014) (CD-ROM), 12 Pages, 2014/06
Irisawa, Keita; Nakagawa, Akinori; Onizawa, Takashi*; Kogawara, Takafumi*; Hanada, Keiji; Meguro, Yoshihiro
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 5 Pages, 2013/09
Times Cited Count:1 Percentile:59.46(Engineering, Environmental)Takahashi, Kuniaki; Kawato, Yoshimi; Hanada, Keiji
JAEA-Review 2009-010, 37 Pages, 2009/07
Regulatory matters for transportation of radioactive waste, legislation, regulations and standards, are checked. We have conducted a study on cost and transportation measure for waste packages from Tokai reprocessing plant and MOX fuel fabrication facilities in Nuclear Fuel Cycle Engineering Laboratories. Here, the number, radioactive inventory and properties of the waste packages are quoted from the second progress report on research and development for TRU waste disposal in Japan. We sorted out the waste packages by the type of packages based on the legislation for transportation of radioactive material. We have studied the packaging for each type of package, and have estimated number of the packages of a conveyance, number of conveyances for transportation of all waste packages. As a result, the waste packages constitutes ca.86% of Industrial package Type 2, ca.2% of Type A package and ca.12% of Type B package. Number of transport by sea for the waste packages is estimated as about 120 times.
Takeuchi, Masayuki; Hanada, Keiji; Aose, Shinichi; Koizumi, Tsutomu; Kato, Toshihiro*
Journal of Physics and Chemistry of Solids, 66(2-4), p.521 - 525, 2005/00
Times Cited Count:38 Percentile:77.51(Chemistry, Multidisciplinary)None
; Kato, Toshihiro*; Hanada, Keiji; ; Aose, Shinichi
JNC TN8430 2002-004, 32 Pages, 2002/12
Pyrochemical reprocessing using molten salts (RIAR process) has been recently developed for spent nuclear oxide fuel and discussed in feasibility study. It is required to improve the corrosion resistance of equipments such as electrolyzer because the process is operated in severe corrosion environment. In this study, the corrosion resistance of ceramic materials was discussed through the thermodynamic calculation and corrosion test. The corrosion test was basically carried out in alkali molten salt under chlorine gas condition. And further consideration about the effects of oxygen, carbon and main fission product's chlorides were evaluated in molten salt. The result of thermodynamic calculation shows most of ceramic oxides have good chemical stability on chlorine, oxygen and uranyl chloride, however the standard Gibb's free energies with carbon have negative value. On the other hand, eleven kinds of ceramic materials were examined by corrosion test, then silicon nitride, mullite and cordierite have a good corrosion resistance less than 0.1mm/y. Cracks were not observed on the materials and flexural strength did not reduce remarkably after 480 hours test in molten salt with Cl-O
bubbling. In conclusion, these three ceramic materials are most applicable materials for the pyrochemical reprocessing process with chlorine gas condition.
Nakagawa, Akinori; Kogawara, Takafumi; Onizawa, Takashi*; Hanada, Keiji; Nakayama, Takuya; Meguro, Yoshihiro
no journal, ,
no abstracts in English
Nakagawa, Akinori; Hanada, Keiji; Meguro, Yoshihiro
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Nakayama, Takuya; Suzuki, Shinji; Hanada, Keiji; Kawato, Yoshimi; Meguro, Yoshihiro
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Kadowaki, Haruhiko; Hanada, Keiji; Watanabe, Yoko; Osone, Osamu; Kato, Atsushi; Meguro, Yoshihiro
no journal, ,
no abstracts in English
Nakayama, Takuya; Hanada, Keiji; Suzuki, Shinji; Kawato, Yoshimi; Meguro, Yoshihiro
no journal, ,
no abstracts in English