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Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.
JAEA-Review 2016-008, 98 Pages, 2016/07
Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.
Tachibana, Mitsuo; Murata, Masato; Tasaki, Tadayuki; Usui, Hideo; Kubota, Shintaro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1987 - 1996, 2015/09
230 various types of nuclear facilities were constructed in JAEA's R&D Institutes or Center until the establishment of the JAEA in 2005. The JAEA has efficiently and systematically decommissioned nuclear facilities that would no longer be required after the establishment of the JAEA. Decommissioning of nuclear facilities in each JAEA's R&D Institutes or Center was continued based on the second midterm plan of the JAEA from FY2010 to FY2014. Decommissioning of 2 nuclear facilities was completed during the second midterm. This report describes current status of decommissioning activities in the JAEA during the second midterm and outline of the decommissioning plan in the third midterm.
Kubota, Shintaro; Izumo, Sari; Usui, Hideo; Kawagoshi, Hiroshi; Koda, Yuya; Nanko, Takashi
JAEA-Technology 2014-022, 22 Pages, 2014/07
Japan Atomic Energy Agency (JAEA) has been developing the PRODIA code which supports to make decommissioning plan and has been preparing evaluation functions. Manpower needs for the dismantling the condenser that had conducted from 2010 to 2012 was analyzed and compared with existing evaluation functions. Applicability of evaluation function for a large scale reactor facility was confirmed in dismantling of the heat insulating materials and feed water heaters and reliability of unit productivity factor was improved. Evaluation function of work for clearance was made in dismantling of pipes and supports. Statistically meaningful data was provided from the dismantling of the condenser. Manpower needs for dismantling of a condenser has positive correlation to the weight of equipment and can be described in linear expression. Reliability of each unit productivity factor will be improved with accumulating actual dismantling data in future.
Izumo, Sari; Usui, Hideo; Kubota, Shintaro; Tachibana, Mitsuo; Kawagoshi, Hiroshi; Takahashi, Nobuo; Morimoto, Yasuyuki; Tokuyasu, Takashi; Tanaka, Yoshio; Sugitsue, Noritake
JAEA-Technology 2014-021, 79 Pages, 2014/07
Japan Atomic Energy Agency has developed PROject management data evaluation code for DIsmantling Activities (PRODIA) to make an efficient decommissioning for nuclear facilities. PRODIA is a source code which provides estimated value such as manpower needs, costs, etc., for dismantling by evaluation formulas according to the type of nuclear facility. Evaluation formulas of manpower needs for dismantling of equipments about reprocessed uranium conversion in Uranium Refining and Conversion Plant are developed in this report. In the result, 7 formulas for prepare process, 24 formulas for dismantling process and 8 formulas for clean-up process are derived. It is confirmed that an unified evaluation formula can be used instead of 8 formulas about dismantling process of steel equipment for uranium conversion process, and 3 types of simplified formula can be used for preparation process and clean-up process respectively.
Kubota, Shintaro; Usui, Hideo; Kawagoshi, Hiroshi
JAEA-Data/Code 2014-010, 84 Pages, 2014/06
Clearance is defined as the removal of radioactive materials or radioactive objects within authorized practices from any further regulatory control by the regulatory body. In Japan, clearance level and a procedure for its verification has been introduced under the Laws and Regulations, and solid clearance wastes inspected by the national authority can be handled and recycled as normal wastes. The most prevalent type of wastes have generated from the dismantling of nuclear facilities, so the Japan Atomic Energy Agency (JAEA) has been developing the Clearance Level Verification Evaluation System (CLEVES) as a convenient tool. The Clearance Data Management System (CDMS), which is a part of CLEVES, has developed to support measurement, evaluation, making and recording documents with clearance level verification. In addition, validation of the evaluation result of the CDMS was carried out by inputting the data of actual clearance activities in the JAEA.
Shibahara, Yuji; Usui, Hideo; Izumo, Sari; Izumi, Masanori; Tezuka, Masashi; Morishita, Yoshitsugu; Kiyota, Shiko; Tachibana, Mitsuo
Nihon Genshiryoku Gakkai Wabun Rombunshi, 12(3), p.197 - 210, 2013/09
As the first step of the applicability inspection of PRODIA Code for dismantling activities in the decommissioning of FUGEN, manpower needs for dismantling activities in FUGEN conducted in 2008 were calculated with conventional calculation formulas which were made by data obtained from JPDR decommissioning program. Since the conventional calculation formula for dismantling of feedwater heater has no applicability, the new calculation formula was constructed by reflecting the work description of dismantling of feedwater heater in FUGEN. It was found that the calculation results with this new formula showed the good agreement with the actual data both of 3rd feedwater heater and 4th one. Based on this discussion, some case studies for dismantling of feedwater heater were conducted.
Izumo, Sari; Usui, Hideo; Tachibana, Mitsuo; Morimoto, Yasuyuki; Takahashi, Nobuo; Tokuyasu, Takashi; Tanaka, Yoshio; Sugitsue, Noritake
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 9 Pages, 2013/09
Times Cited Count:0 Percentile:0.00(Engineering, Environmental)Iimura, Soshi*; Matsuishi, Satoru*; Miyakawa, Masashi*; Taniguchi, Takashi*; Suzuki, Katsuhiro*; Usui, Hidetomo*; Kuroki, Kazuhiko*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; et al.
Physical Review B, 88(6), p.060501_1 - 060501_5, 2013/08
Times Cited Count:26 Percentile:69.73(Materials Science, Multidisciplinary)Muraguchi, Yoshinori; Kanayama, Fumihiko; Usui, Hideo; Izumo, Sari; Tachibana, Mitsuo
JAEA-Technology 2012-035, 69 Pages, 2012/12
Dismantling activities of equipment in JAEA's Reprocessing Test Facility (JRTF) used for wet reprocessing test started from 1996. Glove boxes and hoods installed in the main building were dismantled preferentially for securing temporary place of dismantled waste and dismantling tools by dismantling activities. Of these, 8 glove boxes (glove box group) were installed in room 232 of the main building. The glove box group was dismantled by setting up a large plastic enclosure (greenhouse) for work efficiency. In this report, dismantling procedure and actual data obtained from dismantling activity were arranged about dismantling activity of glove box group of room 232 in 1996. About dismantling activity of glove box group, manpower of the basic work items extracted by classifying into common work items and independent work items were analyzed. In addition, calculation equation was examined concerning dismantling of glove boxes.
Usui, Hideo; Izumo, Sari; Shibahara, Yuji; Morimoto, Yasuyuki; Tokuyasu, Takashi; Takahashi, Nobuo; Tanaka, Yoshio; Sugitsue, Noritake; Tachibana, Mitsuo
Proceedings of International Waste Management Symposia 2012 (WM2012) (CD-ROM), 13 Pages, 2012/02
Dismantling of dry conversion facility in the uranium refining and conversion plant at Ningyo-toge began in 2008. During dismantling activities, project management data have been collected. Establishment of the calculation formula for dismantling of each kind of equipment makes it possible to evaluate manpower for dismantling the whole facility. However, it is not easy to prepare calculation formula for all kinds of equipment in the facility. Therefore, a simpler evaluation method was considered to calculate manpower based on facility characteristics. The results showed promise for evaluating dismantling manpower with respect to each chemical process. To create an effective dismantling plan, it is necessary to carefully consider use of a GH preliminarily. Thus, an evaluation method of project management data such as manpower and secondary waste generation was considered. The results showed promise for evaluating project management data of GH by using established calculation formula.
Maeda, Toshikatsu; Yamaguchi, Tetsuji; Bamba, Tsunetaka; Usui, Hideo
Nihon Genshiryoku Gakkai Wabun Rombunshi, 9(3), p.233 - 242, 2010/09
An experimental approach was proposed to understand the mechanism and model for slow dissolution of high-level radioactive waste glass under disposal conditions where silica is nearly saturated in contacting pore water. Based on an extended literature survey covering recent experimental results on glass dissolution, we have reached a hypothesis that the slow dissolution is limited by diffusion of oxonium ions in an altered layer formed on the glass surface. We suggested several experimental methods such as an elaborate and systematic diffusion experiment using thin glass membranes of tens-of-micrometer thickness to validate the hypothesis. Also pointed out was that dissolution model applicable to glass waste form performance evaluation takes into account the surface area evolution and stability of altered region of the waste form.
Noda, Kenji; Sugimoto, Masayoshi; ; Matsuo, Hideto; Watanabe, Katsutoshi; Kikuchi, Teruo; Usui, Takeshi; Oyama, Yukio; Ono, Hideo; Kondo, Tatsuo
Journal of Nuclear Materials, 191-194, p.1367 - 1371, 1992/00
Times Cited Count:9 Percentile:64.74(Materials Science, Multidisciplinary)no abstracts in English
Izumo, Sari; Usui, Hideo; Tachibana, Mitsuo; Sugitsue, Noritake; Morimoto, Yasuyuki; Tokuyasu, Takashi
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no abstracts in English
Maeda, Toshikatsu; Hotta, Katsutoshi*; Usui, Hideo; Bamba, Tsunetaka
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Usui, Hideo; Tachibana, Mitsuo; Morimoto, Yasuyuki; Takahashi, Nobuo; Tokuyasu, Takashi; Sugitsue, Noritake
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no abstracts in English
Murata, Masato; Katano, Yoshiaki; Usui, Hideo; Kubota, Shintaro
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As of October 2014, four Nuclear Power Plants, such as Tokai-1, Hamaoka Power Station Unit 1, Unit 2 and Fugen, have been carried out decommissioning, and JAEA's facilities, such as JRR-2, JRTF, RHL, PFFF, have been decommissioned, too. This presentation shows the decommissioning strategy and current status of decommissioning in Japan at ANUP2014.
Usui, Hideo; Kobayashi, Hirohide
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Maeda, Toshikatsu; Hotta, Katsutoshi*; Usui, Hideo
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no abstracts in English
Iida, Yoshihisa; Usui, Hideo; Mitsumoto, Yoshibumi; Hoshino, Seiichi; Kadowaki, Mitsushi; Mukai, Masayuki; Yamaguchi, Tetsuji; Tanaka, Tadao
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no abstracts in English
Izumo, Sari; Usui, Hideo; Tachibana, Mitsuo; Morimoto, Yasuyuki; Tanaka, Yoshio; Sugitsue, Noritake; Takahashi, Nobuo; Tokuyasu, Takashi
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no abstracts in English