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Nishino, Shohei; Nishida, Tetsuro; Kawasaki, Ichio; Motohashi, Masahiro; Kambara, Takashi*; Suzuki, Takaichi*; Kinoshita, Masato*
Nihon Hozen Gakkai Dai-20-Kai Gakujutsu Koenkai Yoshishu, p.14 - 21, 2024/08
Steam is used to a process and air conditioning in Nuclear fuel Cycle engineering Laboratories (NCL). The steam is used mainly in Reprocessing Plant, and it is supplied by two steam plumbing. A leak occurred from the steam plumbing in November, 2022. As a result of cause investigation, I estimated that it had leaked by a water hammer caused for the trouble of the steam trap.
Nishino, Shohei; Motohashi, Masahiro; Nishida, Tetsuro; Kawasaki, Ichio
Nihon Hozen Gakkai Dai-19-Kai Gakujutsu Koenkai Yoshishu, p.73 - 79, 2023/08
There are 4-boiler in Nuclear fuel Cycle engineering Laboratories (NCL). These boilers have been operated in the long term over 29 years. There are many water tube as one of many identical components which together make up a boilers. The leakage from water tube have occurred four times in recently. It was presumed that sulfur acid corrosion had caused the leakage. Therefore, to reduce generation of sulfuric acid corrosion, the operation term was changed to long, and regular inspection (non-destructive testing) have been carried out.
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.
Kobayashi, Daisuke; Yamamoto, Masahiko; Nishida, Naoki; Miyoshi, Ryuta; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kato, Keisuke; Nishino, Saki; Kuno, Takehiko; Kitao, Takahiko; et al.
Nihon Hozen Gakkai Dai-18-Kai Gakujutsu Koenkai Yoshishu, p.237 - 240, 2022/07
All gloves attached to glove-box in Tokai Reprocessing Plant have a fixed expiration date and have to be replaced every 4-year. However, degrees of glove deterioration are different depending on its usage environment (frequency, chemicals, radiation, etc.), because of rubber products. Therefore, physical properties such as tensile strength, elongation, hardness of gloves are measured, and the life-time of gloves are estimated. As a result, gloves without any defects in its appearance have enough physical property for acceptance criteria of new glove. The extrapolated physical property of glove is sufficiently larger than the reported values of damaged glove. No deterioration in physical properties of gloves, that are periodically replaced without any defects in its appearance, is observed and the usable life-time of the glove is estimated to be 8 years.
Nishino, Saki; Tsuboi, Masatoshi; Okada, Jumpei; Saegusa, Yu; Omori, Kazuki; Yasuo, Kiyoshi; Seshimo, Kazuyoshi; Domura, Kazuyuki; Yamamoto, Masahiko
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.541 - 548, 2021/07
no abstracts in English
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:31.23(Materials Science, Multidisciplinary)Kawasaki, Masatsugu; Nakajima, Junya; Yoshida, Keisuke; Kato, Saori; Nishino, Sho; Nozaki, Teo; Nakagawa, Masahiro; Tsunoda, Junichi; Sugaya, Yuki; Hasegawa, Rie; et al.
JAEA-Data/Code 2017-004, 57 Pages, 2017/03
In emergency situation of nuclear facilities, we need to estimate the radiation dose due to radiation and radioactivity to grasp the influence range of the accident in the early stage. Therefore, we prepare the case studies of dose assessment for public exposure dose and personal exposure dose and contribute them to emergency procedures. This document covers about accidents of nuclear facilities in Nuclear Science Research Institute and past accident of nuclear power plant, and it can be used for inheritance of techniques of emergency dose assessment.
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:0.00(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.
Shimada, Kenya*; Higashiguchi, Mitsuharu*; Arita, Masashi*; Namatame, Hirofumi*; Taniguchi, Masaki*; Fujimori, Shinichi; Saito, Yuji; Fujimori, Atsushi; Takata, Yasutaka*; Shin, S.*; et al.
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.e57 - e58, 2007/03
We have examined the electronic states of the Kondo semiconductor CeRhAs and the semimetal CeRhSb by means of high-resolution photoemission spectroscopy using tunable photon energies from 40 up to 5948 eV. On the basis of the photon-energy dependence ofthe photoionization cross-section, we have elucidated the p-d-f hybridized states in these compounds.
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:6.41(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:68.34(Physics, Fluids & Plasmas)no abstracts in English
Sekiguchi, Nobutada; Nishino, Osamu*; Wakayama, Naoaki*; Iwasaki, Toshio*; Araki, Hitoshi*; Miyazawa, Tatsuo*
Nihon Genshiryoku Gakkai-Shi, 22(9), p.604 - 615, 1980/00
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。
Nishino, Saki; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kobayashi, Daisuke; Isomae, Hidemi; Sakuma, Shuhei; Takimoto, Misaki; Okuyama, Shun; Unno, Motoyoshi; Kitao, Takahiko
no journal, ,
At the JAEA Tokai Reprocessing facility, especially workers engaged in Plutonium Conversion Development Facility (PCDF) are required strict radiation control due to working environment handling various nuclear material including plutonium (Pu) at short range. Because the equivalent dose limit of the lens of the eye stipulated by Japanese regulations has been revised downwards, we reassessed personal dose equivalent focusing on the lens of the worker's eye. The reassessment results indicate that wearing the appropriate radiation protection glasses is necessary for some workers who handle Pu including waste material in PCDF. Radiation management using protective glasses has started under revised radiation control plan.
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
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