Decommissioning of uranium handling facility for development of nuclear fuel manufacturing equipment

Kageyama, Tomio; Denuma, Akio; Koizumi, Jin*; Odakura, Manabu*; Haginoya, Masahiro*; Isaka, Shinichi*; Kadowaki, Hiroyuki*; Kobayashi, Shingo*; Morimoto, Taisei*; Kato, Yoshiaki*; et al.

JAEA-Technology 2022-033, 130 Pages, 2023/03

JAEA-Technology-2022-033.pdf:9.87MB

Uranium handling facility for development of nuclear fuel manufacturing equipment (Mockup room) was constructed in 1972. The Mockup room has a weak seismic resistance and is deteriorating with age. Also, the original purpose with this facility have been achieved and there are no new development plans using this facility. Therefore, interior equipment installed in this facility had been dismantled and removed since March 2019. After that, the Mockup room was inspected for contamination, and then controlled area in the Mockup room was cancelled on March 29th 2022. A total of 6,549 workers (not including security witnesses) were required for this work. The amount of non-radioactive waste generated by this work was 31,300 kg. The amount of radioactive waste generated by this work was 3,734 kg of combustible waste (103 drums), 4,393 kg of flame resistance waste (61 drums), 37,790 kg of non-combustible waste (124 drums, 19 containers). This report describes about the dismantling and removing the interior equipment in the Mockup room, the amount of waste generated by this work, and procedure for cancellation the controlled area in the facility.

Silicon isotope separation utilizing infrared multiphoton dissociation of SiF irradiated with two-frequency CO laser lights

Yokoyama, Atsushi; Oba, Hironori; Hashimoto, Masashi; Katsumata, Keiichi; Akagi, Hiroshi; Ishii, Takeshi*; Oya, Akio*; Arai, Shigeyoshi*

Applied Physics B, 79(7), p.883 - 889, 2004/11

https://doi.org/10.1007/s00340-004-1642-z

Silicon isotope separation has been done utilizing the Infrared Multiphoton Dissociation of SiF irradiated with two-frequency CO laser lights. The two-frequency excitation method improved the separation efficiency with keeping the high enrichment factors. For example, SiF with the Si fraction of 99.4 % was obtained at 40.0 % dissociation of SiF after the simultaneous irradiation of 100 pulses with 966.23 cm photons (0.089 J/cm) and 954.55 cm photons (0.92 J/cm), while 1000 pulses were needed to obtain 99.0 % of Si at 27.2 % dissociation in the case of single frequency irradiation at 954.55 cm (0.92 J/cm). The single-step enrichment factors of Si and Si increased with increasing SiF pressure. The reason for this enhancement has been discussed in terms of the rotational and vibrational relaxations by collisions with ambient gases.

Study on Present Status ofMeasurement Technologies for Low-level Radioactivity Concentration in Waste

Urayama, Katsumi*; Endo, Yasumi*; Kino, Kenichiro*; Oya, Akio*

JNC TJ8420 2000-006, 68 Pages, 2000/03

JNC-TJ8420-2000-006.pdf:1.94MB

no abstracts in English

Critical experiments and characteristic measurement for JRR-2

JRR-2 Critical Experiments Group; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.

JAERI 1025, 62 Pages, 1962/03

JAERI-1025.pdf:4.6MB

no abstracts in English

Comparison of boronized wall between LHD and JT-60U for optimization of boronization procedure

Ashikawa, Naoko*; Nishimura, Kiyohiko*; Masuzaki, Takashi*; Sagara, Akio*; Oyabu, Nobuyoshi*; Kizu, Kaname; Yagyu, Junichi; Nobuta, Yuji; Ishimoto, Yuki*; Miya, Naoyuki; et al.

no journal, , 

no abstracts in English