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Nishino, Saki; Okada, Jumpei; Watanabe, Kazuki; Furuuchi, Yuta; Yokota, Satoru; Yada, Yuji; Kusaka, Shota; Morokado, Shiori; Nakamura, Yoshinobu
JAEA-Technology 2023-011, 39 Pages, 2023/06
Tokai Reprocessing Plant (TRP) which shifted to decommissioning phase in 2014 had nuclear fuel materials such as the spent fuel sheared powder, the diluted plutonium solution and the uranium solution in a part of the reprocessing main equipment because TRP intended to resume reprocessing operations when it suspended the operations in 2007. Therefore, we have planned to remove these nuclear materials in sequence as Flush-out before beginning the decommissioning, and conducted removal of the spent fuel sheared powder as the first stage. The spent fuel sheared powder that had accumulated in the cell of the Main Plant (MP) as a result of the spent fuel shearing process was recovered from the cell floor, the shearing machine and the distributor between April 2016 and April 2017 as part of maintenance. Removing the recovered spent fuel sheared powder was conducted between June 2022 and September 2022. In this work, the recovered powder was dissolved in nitric acid at the dissolver in a small amount in order to remove it safely and early, and the dissolved solution was sent to the highly radioactive waste storage tanks without separating uranium and plutonium. Then, the dissolved solution transfer route was rinsed with nitric acid and water. Although about 15 years had passed since previous process operations, the removing work was successfully completed without any equipment failure because of the organization of a system that combines veterans experienced the operation with young workers, careful equipment inspections, and worker education and training. Removing this powder was conducted after revising the decommissioning project and obtaining approval from the Nuclear Regulation Authority owing to operating a part of process equipment.
Nishida, Satoru*; Nishino, Soichiro*; Sekine, Masahiko*; Oka, Yuki*; Harjo, S.; Kawasaki, Takuro; Suzuki, Hiroshi; Morii, Yukio*; Ishii, Yoshinobu*
Materials Transactions, 62(5), p.667 - 674, 2021/05
Times Cited Count:5 Percentile:41.35(Materials Science, Multidisciplinary)Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Kikuchi, Masaaki*; Sakauchi, Nobuyuki*; et al.
JAEA-Review 2015-030, 115 Pages, 2015/12
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2014. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Kawasaki, Ichio; Ishiyama, Toru; Nishino, Shohei; Aoki, Masaru*
Boira Kenkyu, (391), p.8 - 14, 2015/06
no abstracts in English
Ozeki, Hidemasa; Isono, Takaaki; Kawano, Katsumi; Saito, Toru; Kawasaki, Tsutomu; Nishino, Katsumi; Okuno, Kiyoshi; Kido, Shuichi*; Semba, Tomoyuki*; Suzuki, Yozo*; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200804_1 - 4200804_4, 2015/06
Times Cited Count:0 Percentile:0(Engineering, Electrical & Electronic)Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Goto, Ichiro*; Kibe, Satoshi*; et al.
JAEA-Review 2014-040, 115 Pages, 2015/01
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Sumiya, Shuichi; Watanabe, Hitoshi; Miyagawa, Naoto; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki; Otani, Kazunori*; Hiyama, Yoshinori*; et al.
JAEA-Review 2013-041, 115 Pages, 2014/01
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2012, from 1st April 2012 to 31st March 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Ueno, Kenichi; Matsui, Kunihiro; Nishino, Toru; Isono, Takaaki; Okuno, Kiyoshi
Plasma and Fusion Research (Internet), 8(Sp.1), p.2405062_1 - 2405062_5, 2013/05
Japan Domestic Agency (JADA) for ITER will procure toroidal field (TF) coil structures and winding packs, and assemble them into a final TF coil configuration. Because the manufacturing schedule of the TF coils is on a critical path toward the first plasma of ITER, coil manufacturing must be successful and proceed on schedule. Therefore, risk assessment and management for the manufacturing are vital. JADA performed a risk assessment on the basis of past manufacturing experiences and risk mitigation policy for ITER. The results show that risks can be mitigated to a level that we can assure sufficint quality of the TF coil by sound design, manufacturing and quality management processes developed through R&D activities, and the use of prototypes.
Tobita, Shigeharu; Nishino, Kazunari; Sumino, Kozo; Ogawa, Toru
UTNL-R-0453, p.2_1 - 2_10, 2006/03
no abstracts in English
Isozaki, Kazunori; Ogawa, Toru; Nishino, Kazunari; Kaito, Yasuaki; Ichige, Satoshi; Sumino, Kozo; Suto, Masayoshi; Kawahara, Hirotaka; Suzuki, Toshiaki; Takamatsu, Misao; et al.
JNC TN9440 2005-003, 708 Pages, 2005/05
Periodic safety review (Review of the aging management) which consisted of Technical review on aging for the safety related structures, systems and components and Establish a long term maintenance program was carried out up to April 2005.1. Technical review on aging for the safety related structures, systems and components It was technically confirmed to prevent the loss of function of the safety related structures, systems and components due to aging phenomena, which (1) irradiation damage, (2) corrosion, (3) abrasion and erosion, (4) thermal aging, (5) creep and fatigue, (6) Stress Corrosion Cracking, (7) insulation deterioration and (8) general deterioration, under the periodic monitoring or renewal of them 2. Establish a long term maintenance program The long term maintenance program during JPY2005 to 2014 were established based on the technical review on aging for the safety related structures, systems and components. It was evaluated that the inspection or renewal based on the long term maintenance program, in addition to the spontaneous inspection long-term schedule of the long term voluntary inspection plan, could prevent the loss of function of the safety related structures, systems and components in future.
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count:2 Percentile:6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Chujo, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
no abstracts in English
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Cho, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
Times Cited Count:33 Percentile:69.14(Physics, Fluids & Plasmas)no abstracts in English
Nishino, Shohei; Ishiyama, Toru; Kawasaki, Ichio
no journal, ,
The purpose of this R&D is the development of removal method for the deposit and the countermeasure of corrosion by solute in the boiler system. In the boiler system, sulfur and iron oxide accumulated on the bottom and stiffened on there. Because the property of this deposit changed to strong acidity, then the generating tube was corroded by it. And the leakage, occurred at generating tube, was found at Dec. 2011. The property of deposit was too hard to remove by pressurized water, and width of each pipe was too narrow to remove by mechanical method, because there was several thousands of generating tube every 30 mm on the bottom. Therefore the effect of lab examination, corrosion test based on materials of the generated tube, was evaluated.
Nakano, Masanori*; Muraki, Shinsaku*; Nishino, Toru*; Chikaishi, Naoki*; Mikami, Takashi*; Shibata, Takuya; Hoshina, Hiroyuki; Saiki, Seiichi; Ueki, Yuji; Kasai, Noboru; et al.
no journal, ,
no abstracts in English
Isono, Takaaki; Kawano, Katsumi; Ozeki, Hidemasa; Sato, Minoru; Saito, Toru; Nishino, Katsumi
no journal, ,
Japan Atomic Energy Agency (JAEA) has fabricated a test coil to evaluate superconducting performance of the conductor used for Central Solenoid (CS) of the International Thermonuclear Experimental Reactor (ITER) system. The coil is a 9-turn single layer solenoid coil with a 1.5-m diameter and will be inserted and tested in the Central Solenoid Model Coil (CSMC) test facility in JAEA. The conductor is cable-in-conduit type and has a square shape of 49 mm. The cable is composed of 576 NbSn strands and 288 copper strands. The conductor will be operated at 13-T magnetic field and 40 kA operating current. Fabrication sequence of the coil is; (1) winding of 1.5 m diameter, (2) fabrication of terminals, (3) heat treatment to generate superconductor, (4) turn insulation, (5) ground insulation, (6) assemble of structures and (7) installation of instruments. Before fabrication of the coil, trial coil was fabricated using a dummy conductor to demonstrate fabrication procedure. Fabrication results of trial and the test coil will be presented.
Ozeki, Hidemasa; Isono, Takaaki; Kawano, Katsumi; Saito, Toru; Kawasaki, Tsutomu; Nishino, Katsumi; Okuno, Kiyoshi; Kido, Shuichi*; Semba, Tomoyuki*; Suzuki, Yozo*; et al.
no journal, ,
no abstracts in English
Nabara, Yoshihiro; Suwa, Tomone; Ozeki, Hidemasa; Sakurai, Takeru; Kajitani, Hideki; Iguchi, Masahide; Hemmi, Tsutomu; Shimono, Mitsugu; Ebisawa, Noboru; Sato, Minoru; et al.
no journal, ,
no abstracts in English
Isono, Takaaki; Kawano, Katsumi; Ozeki, Hidemasa; Saito, Toru; Nabara, Yoshihiro; Suwa, Tomone; Shimono, Mitsugu; Ebisawa, Noboru; Sato, Minoru; Uno, Yasuhiro; et al.
no journal, ,
JAEA is procuring conductors for ITER Central Solenoid (CS) and has evaluated its superconducting performance using CS Model Coil Test facility. We measured Tcs values during cyclic charge of 16,000 cycles and warm-up and cool-down cycle of 3 times. And we measured effect of coil deformation by electro-magnetic force on Tcs values and performed quench test. In this presentation, test method will be reported.
Nishino, Yuki; Kuramoto, Shimpei; Naruse, Keiji; Nishino, Hajime; Goto, Takehiro; Takeuchi, Toru
no journal, ,
no abstracts in English
川崎 一男; 石山 道; 西野 将平
田村 欣也*
【課題】水管ボイラ内が複雑かつ狭隘であっても、安価で、かつ簡略な構造で、洗浄対象物である水管に付着した堆積物の剥離を効率よく実現できる水管ボイラ内の堆積物除去方法及び装置を提供する 【解決手段】水管ボイラ内に圧力を印加した洗浄体を噴射させ、水管部外表面を洗浄する水管ボイラ内の堆積物除去方法であって、ドライアイスと圧縮空気とを混合する洗浄機本体と、前記洗浄機本体で製造したドライアイスと圧縮空気との混合気体である洗浄体を延長管ならびに噴射ノズルによって水管部外表面に吹き付けるノズル部とで構成し、水管部外表面に付着した堆積物を剥離する。