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Aono, Ryuji; Mitsukai, Akina; Tsuchida, Daiki; Konda, Miki; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2023-002, 81 Pages, 2023/05
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field as trench and pit. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed the samples generated from JRR-2, JRR-3 and Hot laboratory facilities. In this report, we summarized the radioactivity concentrations of 20 radionuclides (H,
C,
Cl,
Co,
Ni,
Sr,
Nb,
Tc,
Ag,
I,
Cs,
Eu,
Eu,
U,
U,
Pu,
Pu,
Pu,
Am,
Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2020.
Tobita, Minoru*; Haraga, Tomoko; Sasaki, Takayuki*; Seki, Kotaro*; Omori, Hiroyuki*; Kochiyama, Mami; Shimomura, Yusuke; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2019-016, 72 Pages, 2020/02
In the future, radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried for the near surface disposal. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the time it starts disposal. In order to contribute to this work, we collected and analyzed the samples generated from JRR-2, JRR-3 and Hot laboratory facilities. In this report, we summarized the radioactivity concentrations of 25 radionuclides (H,
C,
Cl,
Co,
Ni,
Sr,
Nb,
Mo,
Tc,
Ag,
Sn,
I,
Cs,
Eu,
Eu,
U,
U,
U,
Pu,
Pu,
Pu,
Pu,
Am,
Am,
Cm) which were obtained from radiochemical analysis of those samples.
Hayashi, Hirokazu; Izumo, Sari; Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro
JAEA-Technology 2018-001, 66 Pages, 2018/06
It is necessary to establish evaluation methodology of radioactivity concentrations of each radionuclide in waste packages for operation of the Near-surface Trench disposal and Sub-surface Pit disposal facility in near future, which has been preparing for low-level radioactive wastes generated from research facilities in JAEA. The radionuclides containing in waste packages generated from both JRR-2 and JRR-3, which are H-3, C-14, Cl-36, Co-60, Ni-63, Sr-90, Nb-94, Tc-99, Ag-108m, I-129, Cs-137, Eu-152, Eu-154, U-234, U-238, Pu-239+240, Pu-238+Am-241, Cm-243+244, were evaluated their density based on radiochemical analysis data, and the Evaluation Methodology of the Radioactivity Concentration such as Scaling Factor method and mean activity concentration method was studied in this report.
Tachibana, Mitsuo; Kishimoto, Katsumi; Shiraishi, Kunio
International Nuclear Safety Journal (Internet), 3(4), p.16 - 24, 2014/11
Three research reactors were permanently shut down in the Nuclear Science Research Institute (NSRI) of the Japan Atomic Energy Agency (JAEA) as of October 2014. Safe storage or one-piece removal method was applied to decommissioning of these research reactors depending on decommissioning cost and utilization of facilities and so on. Various kinds of data and experiences were obtained through decommissioning of these research reactors. This report shows data and experiences on the research reactors decommissioning in the NSRI of the JAEA.
Suzuki, Takeshi; Nakano, Masahiro; Okawa, Hiroshi; Terunuma, Akihiro; Kishimoto, Katsumi; Yano, Masaaki
JAERI-Tech 2005-018, 84 Pages, 2005/03
no abstracts in English
Tomii, Hiroyuki; Matsuo, Kiyoshi*; Shiraishi, Kunio; Kato, Rokuro; Watabe, Kozo; Higashiyama, Yutaka; Nagane, Satoru*; Hanawa, Yukimitsu*
JAERI-Tech 2005-017, 65 Pages, 2005/03
no abstracts in English
Kishimoto, Katsumi; Arigane, Kenji*
JAERI-Tech 2005-016, 83 Pages, 2005/03
Revaluation to activation activity of reactor evaluated at the notification of dismantling submitted in 1997 was carried out in JRR-2 where decommissioning was advanced now. In the revaluation, estimation accuracy on neutron streaming at various horizontal experimental tubes was improved by applying 3 dimensional model to neutron transport calculation that had been carried out by 2 dimensional model, and calculating with TORT. As the result, excessive overestimations on horizontal experimental tubes and biological shield that had greatly contributed to total activation activity in evaluation at the notification of dismantling was revised, sum of their activation activities in the revaluation decreased to 1/18(case after 1 year from the permanent shutdown of reactor) of evaluation at the notification of dismantling, and the structural materials that had large activation activity were changed. By the above, it was shown that introducing 3 dimensional model was effective in evaluation on activation activity of the research reactor that had a lot of various experimental tubes.
Nakano, Masahiro; Okawa, Hiroshi; Suzuki, Takeshi; Kishimoto, Katsumi; Terunuma, Akihiro; Yano, Masaaki
Dekomisshoningu Giho, (30), p.11 - 24, 2004/09
Japan Research Reactor No.2(JRR-2), heavy water moderated and cooled tank type research reactor with maximum thermal power of 10MW,was operated for over 36 years, and was permanently shut down in December, 1996. In 1997, decommissioning plan was submitted to the STA, and dismantling was begun. Decommissioning program of JRR-2 is divided into 4 phases. Phase 1, 2 had already been completely finished without any trouble. Furthermore, the phase 3 was also finished in February, 2004 as planned. On exposure of worker in phase 1, 2 and 3, it was achieved to control lower than the estimate. On exposure of worker in phase 1, 2 and 3, it was achieved to control lower than the estimate. Reactor will be removed in phase 4 by one piece removal technique. The reactor building is planned to use effectively as a hot experimental facilities after decommissioning. The decommissioning plan was changed that the reactor would be kept in safety storage.
Nakano, Masahiro; Arigane, Kenji; Okawa, Hiroshi; Suzuki, Takeshi; Kishimoto, Katsumi; Terunuma, Akihiro; Yano, Masaaki; Sakuraba, Naotoshi; Oba, Nagamitsu
JAERI-Tech 2003-072, 92 Pages, 2003/08
The decommissioning plan of the Japan Research reactor No2(JRR-2), decommissioning activities until the first half of phase-3, radioactive wastes and exposure dose of workers are described in this report. Since the first criticality in October 1960, JRR-2 had been operated about 36 years for various experiments. However, JRR-2 was permanent shutdown in December 1996 based on JAERI's long term plan, and the decommissioning of the JRR-2 was started in August 1997. Decommissioning of the JRR-2 was planed for 11 years from 1997 to 2007 and the program was divided into 4 phases. The decommissioning activities of the phase-1, phase-2 and the first half of phase-3 had already completed as planned in March 1998, February 2000, March 2002, respectively. The decommissioning activities of the later half of Phase-3 (dismantling of the reactor cooling systems) are carrying out at present time with planed 2002 and 2003 fiscal years.
Yanagihara, Satoshi; Tachibana, Mitsuo; Miyajima, Kazutoshi
Proceedings of International Conference; Decommissioning Challenges (CD-ROM), 8 Pages, 2003/00
Several decommissioning projects are on going and studies on decommissioning issues are in progress in JAERI. The JPDR and JRTF decommissioning projects have been set up as demonstration programs for future decommissioning large nuclear facilities. Therefore, efforts have been made not only to dismantle the facilities but also to collect data and lessons learnt on dismantling activities. The data and lessons learnt have been analyzed to produce the database for future decommissioning projects by categorizing into manpower expenditure, radiation dose and waste generation in project data, and safety aspect, waste management, work efficiency considerations in lessons learnt. respectively. The feedback experience has been effectively contributed to various areas on decommissioning such as studies on regulatory systems and planning of other dismantling projects. This paper deals with decommissioning experience and lessons learned in JAERI.
Motoishi, Shoji; Kobayashi, Katsutoshi; Saeki, Hideya*
JAERI-Tech 2000-070, 34 Pages, 2000/12
no abstracts in English
Bamba, Masao
Dekomisshoningu Giho, (22), p.6 - 19, 2000/08
no abstracts in English
Iwashita, Mitsushige*; Arigane, Kenji; Kishimoto, Katsumi; Seiki, Y.*; Fukumura, Nobuo*; Mio, K.*
Journal of Nuclear Science and Technology, 37(Suppl.1), p.372 - 378, 2000/03
no abstracts in English
Kishimoto, Katsumi; Bamba, Masao; Arigane, Kenji
JAERI-Conf 99-006, p.96 - 101, 1999/08
no abstracts in English
Kishimoto, Katsumi; Bamba, Masao; Arigane, Kenji
Proc. of 1999 Workshop on the Utilization of Research Reactors, p.96 - 101, 1999/00
no abstracts in English
Kaieda, Keisuke; ; Arigane, Kenji
Genshiryoku Nenkan '98/'99-Nen Ban, P. 216, 1998/12
no abstracts in English
Enerugi Fuoramu, 43(516), P. 137, 1997/12
no abstracts in English
; Nakajima, Teruo; ; ; ;
Advances in Neutron Capture Therapy, 1, p.326 - 330, 1997/00
no abstracts in English
;
UTNL-R-0333, 0, P. NO.10, 1996/03
no abstracts in English
Yonezawa, Chushiro; ; ; Sasajima, Fumio; R.P.Putra*
2nd Int. k Users Workshop Proceedings, 0, p.129 - 133, 1996/00
no abstracts in English