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Shibanuma, Tomohiro; Hirano, Hiroshi*; Kimura, Yasuhisa; Aita, Takahiro; Yoshida, Masato; Nagai, Yuya; Kitamura, Akihiro
Hoken Butsuri (Internet), 58(2), p.91 - 98, 2023/08
We developed new containment tents that are more easily assembled and effectively functioned, by improving and refurbishing the shortcomings of the conventional tents. The new tents have been already tested in the real airborne contamination situation occurred at the plutonium fuel fabricating facility. The tents appropriately functioned for intended use but other shortcomings emerged and therefore we had modified the structure of the tents further.
Nagai, Yuya; Shuji, Yoshiyuki; Kawasaki, Takeshi; Aita, Takahiro; Kimura, Yasuhisa; Nemoto, Yasunori*; Onuma, Takeshi*; Tomiyama, Noboru*; Hirano, Koji*; Usui, Yasuhiro*; et al.
JAEA-Technology 2022-039, 117 Pages, 2023/06
Japan Atomic Energy Agency (JAEA) manages wide range of nuclear facilities. Many of these facilities are required to be performed adjustment with the aging and complement with the new regulatory standards and the earthquake resistant, since the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station accident. It is therefore desirable to promote decommissioning of facilities that have reached the end of their productive life in order to reduce risk and maintenance costs. However, the progress of facility decommissioning require large amount of money and radioactive waste storage space. In order to address these issues, JAEA has formulated a "The Medium/Long-Term Management Plan of JAEA Facilities" with three pillars: (1) consolidation and prioritization of facilities, (2) assurance of facility safety, and (3) back-end countermeasures. In this plan, Plutonium Fuel Fabrication Facility has been selected as primary decommissioned facility, and dismantling of equipment in the facilities have been underway. In this report, size reduction activities of the glove box W-9 and a part of tunnel F-1, which was connected to W-9, are presented, and the obtained findings are highlighted. The glovebox W-9 had oxidation & reduction furnace, and pellet crushing machine as equipment interior. The duration of activity took six years from February 2014 to February 2020, including suspended period of 4 years due to the enhanced authorization approval process
Asakawa, Jun; Hirano, Hiroshi*; Nagai, Yuya; Aita, Takahiro; Shibanuma, Tomohiro; Kimura, Yasuhisa
Hoken Butsuri (Internet), 57(2), p.93 - 101, 2022/09
In the dismantling work of glove boxes (GBs) contaminated with radioactive materials at the nuclear fuel facilities, plastic tents are constructed around the entire GBs, and workers putting on air-fed suits (AFS) (hereinafter referred to as AFS worker) dismantle the GBs and interior equipment by using cutting tools. If an AFS worker suddenly feels sick during the work and the worker is unable to move independently, it will be necessary to exit in the shortest time from the viewpoint of respecting human life. In this case, a lot of radioactive materials may be brought into the contamination control room, thus the room and the equipment of the workers may be contaminated. Consequently, until the decontamination work is completed, the other AFS workers will have to put on AFS and wait for long time, which puts a strain on the workers. In this report, the plastic enclosure tents for body decontamination developed in JAEA were used as a new contamination control room replaced the contaminated one, and the procedure to quickly exit the remaining AFS workers was proposed. As a result, we confirmed that it was possible to greatly reduce the waiting time of the other AFS workers who is forced to wait in the dismantling area.
Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Kobayashi, Masanori*; Muto, Toshiya*; Matsuba, Shunya*; Sakanaka, Shogo*; Sato, Kotaro*; Saito, Yoshio*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.860 - 862, 2009/08
A newly 500 kV electron gun (2nd - 500 kV gun) for an ERL light source is designed at KEK. A new concept and state of-the-art technologies of vacuum system, ceramic insulators, high voltage power supply, photocathode and preparation system will be employed. The details are described in this report.
平野 宏志; 木村 泰久; 柴沼 智博; 會田 貴洋; 永井 佑哉; 浅川 潤; 吉田 将冬; 周治 愛之
南 明則*
【課題】迅速に組み立て可能な接続テントを提供する。 【解決手段】接続テント(1)は、一対の第1側面フレーム(11、12)及び第1天面フレーム(13)を有する門型フレーム(10)と、第2側面フレーム(21)及び第2天面フレーム(22)を有するL型フレーム(20)と、門型フレーム(10)及びL型フレーム(20)で囲まれた内部空間に収容可能であり、開閉可能な複数の出入口が側面に形成された箱型の部屋テントとを備え、複数の出入口それぞれは、門型フレーム(10)及びL型フレーム(20)の側面に形成された複数の開口のいずれかに対面している。
木村 泰久; 平野 宏志; 柴沼 智博; 吉田 将冬; 永井 佑哉; 塙 幸雄; 周治 愛之; 會田 貴洋
南 明則*
【課題】ポート本体とグローブとを間に隙間が生じるのを適切に防止できるポートキャップを提供する。 【解決手段】ポートキャップ(20)は、取付開口(8)から突出する筒体(16)と、先端部が筒体(16)を通じてグローブボックスの内部空間に進入し、基端部が筒体(16)の外周面側に折り返されたグローブ(12)と、折り返されたグローブ(12)と筒体(16)の外周面との間を封止するOリング(13A,13B)及びクランプリング(14)とを備えるグローブポート(10)に取り付けられ、グローブ(12)の内側から筒体(16)に圧入される内筒(21)と、筒体(16)の外側を覆う外筒(22)と、内筒(21)及び外筒(22)の端部同士を接続するフランジ(23)とを備え、内筒(21)の外周面側の先端(21A)は、R面取りされている。
Nagai, Yuya; Yoshida, Masato
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no abstracts in English
Aita, Takahiro; Hirano, Hiroshi*; Kimura, Yasuhisa; Shibanuma, Tomohiro; Yoshida, Masato; Nagai, Yuya; Asakawa, Jun; Shuji, Yoshiyuki
no journal, ,
The newly developed Plastic enclosure tents have reliable airtightness and can be set up in a short time with the small number of persons. Also, in order to prevent the spread of contamination, the exhaust device secures the internal airflow line, and the radiation management device measures the concentration of radioactive materials in the air are in real time. Furthermore, by setting up a multiple of evacuation routes, the decontamination time is shortened even when there are many contaminated persons. Therefore, it is possible to quickly evacuate the contaminated person by having both radiation safety and setting up that can quickly respond to a large-scale body contamination accident.
Tsubota, Yoichi; Kimura, Yasuhisa; Nagai, Yuya; Kojima, Sho*; Tokonami, Shinji*; Nakagawa, Takahiro
no journal, ,
Nagai, Yuya
no journal, ,
no abstracts in English
Asakawa, Jun; Ono, Yosuke; Shibanuma, Tomohiro; Aita, Takahiro; Nagai, Yuya
no journal, ,
no abstracts in English