Decommissioning state of Plutonium Fuel Fabrication Facility; Dismantling the glove box W-9 and equipment interior, and a part of tunnel F1

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

JAEA-Technology-2022-039.pdf:11.96MB

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

The Present situation and future prospects of groundwater colloids studies on the performance assessment of geological disposal of radioactive wastes in Japan

Nagao, Seiya*; Niibori, Yuichi*; Tanaka, Tadao; Sasaki, Takayuki*; Saito, Takumi*; Kirishima, Akira*; Yoshikawa, Hideki; Iijima, Kazuki; Hama, Katsuhiro; Iwatsuki, Teruki; et al.

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 20(1), p.3 - 14, 2013/06

https://doi.org/10.3327/jnuce.20.3

This paper shows a current status of groundwater colloids studies on the performance assessment of geological disposal of radioactive wastes in Japan, and summaries realistic approach of the colloids studies at a substantial research network for Japanese universities and institutes.

Photoemission and core-level absorption spectroscopy of FeNbS

Saito, Yuji; Kobayashi, Keisuke*; Fujimori, Atsushi; Yamamura, Yasuhisa*; Koyano, Mikio*; Tsuji, Toshihide*; Katayama, Shinichi*

Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.829 - 832, 2005/06

https://doi.org/10.1016/j.elspec.2005.01.186

no abstracts in English

Radiation control on wastes recovery work in wastes storage pit

Ito, Yasuhisa; Noda, Kimio; ;

JNC TN8410 2001-018, 67 Pages, 2001/04

JNC-TN8410-2001-018.pdf:2.96MB

There are waste storage pits where non-radioactive wastes generated from plutonium fuel facilities were stored in JNC Tokai Works. But radioactive wastes were found in one of the pit during wastes arrangement works. Therefore we set the pit temporary controlled area and recovered wastes from it. This report describes the radiation control technique of recovery work in detail.

TONO MINE

Saito, Hiroshi; Yusa, Yasuhisa; Koide, Kaoru; ; ; Hama, Katsuhiro;

JNC TN7400 2000-010, 40 Pages, 1999/09

JNC-TN7400-2000-010.pdf:1.53MB

This technical report provides a comprehensive presentation the "Geoscientific Studies" performed since 1986, and new work for the "Earthquake Frontier Research for Terrestrial Subsurface" programme performed since 1995 in and around the Tono Mine, Gifu Prefecture. This technical report also provides fieldstop descriptions for visits to the Tono Mine. The descriptions are attached at the end of this report.

An Experience of alpha-radioactivity monitoring aiming at -rays from Am-241 in airborne effluent

Ito, Yasuhisa; Mikami, Satoshi; Miyauchi, Toru; Akiyama, Kiyomitsu; Kobayashi, Hirohide; Kozawa, Tomoyasu*; Yokota, Tomokazu*

no journal, , 

no abstracts in English

Radiation protection feature and research at Tokai reprocessing plant

Momose, Takumaro; Endo, Kuniaki; Ito, Yasuhisa; Yamashita, Tomoyuki; Namiki, Atsushi; Sanada, Yukihisa; Akiyama, Kiyomitsu; Takeishi, Minoru; Tago, Itaru; Furuta, Sadaaki

no journal, , 

The first reprocessing pilot plant in Japan (Tokai Reprocessing Plant; TRP) has been operated since 1977 at Nuclear Fuel Cycle Engineering Laboratories, JAEA. General radiation protection in TRP is performed with continuous monitoring and sampling methods. The continuous monitors measuring -ray, neutron, particulate alpha and beta nuclides in the air are installed in the radiation controlled area as a central monitoring system to prevent from unnecessary exposure. Air and water effluents from the TRP are also monitored by continuous monitors or sampling methods to comply with regulations. In addition to this, environmental monitoring has been carried out to assess influences on public and environment by the plant operation. A feature of radiation protection and its recent relevant researches at TRP will be introduced in this presentation.

Development of the surface monitor for simultaneous measurement of alpha and beta rays

Ito, Yasuhisa; Akiyama, Kiyomitsu; Momose, Takumaro; Taguchi, Shizuo*; Ishii, Shinya*

no journal, , 

no abstracts in English

Effect of air-breathing system with reed valves on thrust of microwave rocket

Komatsu, Reiji*; Saito, Shohei*; Fukunari, Masafumi*; Yamaguchi, Toshikazu*; Komurasaki, Kimiya*; Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Sakamoto, Keishi

no journal, , 

no abstracts in English

Expansion of the repetitive pulse frequency limitation of microwave rocket

Kurita, Satoshi*; Saito, Shohei*; Fukunari, Masafumi*; Yamaguchi, Toshikazu*; Komurasaki, Kimiya*; Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Sakamoto, Keishi

no journal, , 

no abstracts in English