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Aono, Ryuji; Haraga, Tomoko; Kameo, Yutaka
JAEA-Technology 2024-006, 48 Pages, 2024/06
In the future, radioactive waste which generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried for the near surface disposal. It is necessary to establish the method to evaluate the radioactivity concentrations of the radioactive wastes. In this work, we studied the evaluation methodology of the radioactivity concentrations in concrete waste generated from JPDR. In order to construct the evaluation methodology of the radioactivity concentration, the validity of the evaluation methods was confirmed by mainly theoretical calculation and using the result of radiochemical analysis. Correcting the theoretical calculations using results of nuclide analysis, it is possible to evaluate the radioactivity concentrations of nuclides preliminary selected.
Tobita, Minoru*; Goto, Katsunori*; Omori, Takeshi*; Osone, Osamu*; Haraga, Tomoko; Aono, Ryuji; Konda, Miki; Tsuchida, Daiki; Mitsukai, Akina; Ishimori, Kenichiro
JAEA-Data/Code 2023-011, 32 Pages, 2023/11
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 the study of radioactivity concentration evaluation methods for radioactive wastes generated from nuclear research facilities, we collected and analyzed concrete samples generated from JRR-3, JRR-4 and JAERI Reprocessing Test Facility. In this report, we summarized the radioactivity concentrations of 23 radionuclides (H,
C,
Cl,
Ca,
Co,
Ni,
Sr,
Nb,
Ag,
Cs,
Ba,
Eu,
Eu,
Ho,
U,
U,
U,
Pu,
Pu,
Pu,
Am,
Am,
Cm) which were obtained from radiochemical analysis of the samples in fiscal years 2021-2022.
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*; Konda, Miki; Omori, Takeshi*; Nabatame, Tsutomu*; Onizawa, Takashi*; Kurosawa, Katsuaki*; Haraga, Tomoko; Aono, Ryuji; Mitsukai, Akina; Tsuchida, Daiki; et al.
JAEA-Data/Code 2022-007, 40 Pages, 2022/11
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. 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 concrete, ash, ceramic and brick samples generated from JRR-3, JRR4 and JRTF facilities. In this report, we summarized the radioactivity concentrations of 24 radionuclides (H,
C,
Cl,
Ca,
Co,
Ni,
Sr,
Nb,
Tc,
Ag,
I,
Cs,
Ba,
Eu,
Eu,
Ho,
U,
U,
Pu,
Pu,
Pu,
Am,
Am,
Cm) which were obtained from radiochemical analysis of the samples in fiscal years 2020-2021.
Tsuchida, Daiki; Mitsukai, Akina; Aono, Ryuji; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2022-004, 87 Pages, 2022/07
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until by the beginning of disposal. In order to contribute to this work, we collected and analyzed samples generated from JPDR, JRR-3 and JRR-4. In this report, radioactivity concentrations of 20 radionuclides (H,
C,
Cl,
Co,
Ni,
Sr,
Nb,
Tc,
Ag,
I,
Cs,
Eu,
Eu,
U,
U,
Pu,
Pu,
Am,
Cm) were determined based on radiochemical analysis and summarized as basic data for the study of evaluation method of radioactive concentration.
Kochiyama, Mami; Sakai, Akihiro
JAEA-Technology 2022-009, 56 Pages, 2022/06
It is necessary to evaluate radioactivity inventory in wastes before disposal of low-level radioactive wastes generated from dismantling research reactors. It is efficient for owners of each research reactor to use a common radioactive evaluation method in order to comply with the license application for disposal facility. In this report, neutron transport and activation calculations were carried out for the Rikkyo University research reactor in order to examine a common radioactivity evaluation method for burial disposal of radioactive wastes generated by dismantling. We adopted the neutron transport codes DORT and MCNP and the activation code ORIGEN-S with cross-section libraries based on JENDL-4.0 and JENDL/AD-2017. The radioactivity concentrations obtained by the radiochemical analysis and both calculation codes were in agreement by 0.4 to 3 times. Therefore, by appropriately considering this difference, the radioactivity evaluation method by DORT, MCNP and ORIGEN-S can be applied to the radioactivity evaluation for buried disposal. In order to classify wastes from dismantling by clearance or buried disposal method according to their radioactivity levels, we also created radioactivity concentration distributions in the concrete area and graphite thermal column area.
Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2021-013, 30 Pages, 2021/12
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. 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 concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides (H,
C,
Cl,
Ca,
Co,
Ni,
Sr,
Nb,
Ag,
Cs,
Eu,
Eu,
Ho,
U,
U,
Pu,
Pu,
Pu,
Am,
Am,
Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.
Kochiyama, Mami; Okada, Shota; Sakai, Akihiro
JAEA-Technology 2021-010, 61 Pages, 2021/07
It is necessary to evaluate the radioactivity inventory in wastes in order to dispose of radioactive wastes generated from dismantling nuclear reactor in the shallow ground. In this report, we examined radioactivity evaluation method for near surface disposal about biological shield concrete near the core generated from the dismantling of JPDR. We calculated radioactive concentration of the target biological concrete using the DORT code and the ORIGEN-S code, and we estimated radioactivity concentration Di (Bq/t). For DORT calculation, the cross-section library created from the MATXSLIB-J40 file from JENDL-4.0 was used, and for ORIGEN-S, the attached library of SCALE6.0 was used. As a result of comparing the calculation results of the radioactivity concentration with the past measured values in the radial direction and the vertical direction, we found that the trends were generally the same. We calculated radioactive concentration of the target biological concrete Di (Bq/t), and we compared with the estimated Ci (Bq/t) equivalent to the dose criteria of trench disposal calculated for 140 nuclides. As a result we inferred that the except for about 2% of target waste could be disposed of in the trench disposal facility. We also preselected important nuclides for trench disposal based on the ratios (Di/Ci) for each nuclide, H-3, C-14, Cl-36, Ca-41, Co-60, Sr-90, Eu-152 and Cs-137 were selected as important nuclides.
Tsuchida, Daiki; Haraga, Tomoko; Tobita, Minoru*; Omori, Hiroyuki*; Omori, Takeshi*; Murakami, Hideaki*; Mitsukai, Akina; Aono, Ryuji; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2020-022, 34 Pages, 2021/03
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. 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 concrete samples generated from JRR-3 and JPDR. In this report, we summarized the radioactivity concentrations of 22 radionuclides(H,
C,
Cl,
Ca,
Co,
Ni,
Sr,
Nb,
Ag,
Ba,
Cs,
Eu,
Eu,
Ho,
U,
U,
Pu,
Pu,
Am,
Am,
Cm) which were obtained from radiochemical analysis of the samples.
Aono, Ryuji; Mitsukai, Akina; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2020-006, 70 Pages, 2020/08
Radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried at the near surface disposal field. 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 JPDR and JRR-4. In this report, we summarized the radioactivity concentrations of 19 radionuclides (H,
C,
Cl,
Co,
Ni,
Sr,
Nb,
Tc,
Ag,
I,
Cs,
Eu,
Eu,
U,
U,
Pu,
Pu,
Am,
Cm) which were obtained from radiochemical analysis of those samples.
Sumita, Junya; Sawa, Kazuhiro; Tsuchie, Yasuo*; Urakami, Masao*; Kunitomi, Kazuhiko
JAERI-Tech 2002-104, 23 Pages, 2003/02
This report describes the result of study on disposal method of graphite blocks in future block-type reactor. Present study was carried out within a framework of joint research, "Research of Modular High Temperature Gas-cooled Reactors (No. 3)", between Japan Atomic Energy Research Institute (JAERI) and the Japan Atomic Power Company (JAPCO), in 2000. In this study, activities in fuel and reflector graphite blocks were evaluated and were compared with the disposal limits defined as low-level of radioactive waste. As a result, it was found that the activity for only C-14 was higher than disposal limits for the low-level of radioactive waste and that the amount of air in the graphite is important to evaluate precisely of C-14 activity. In addition, spent fuels can be stored in air-cooled condition at least after two years cooling in the storage pool.
Okuno, Hiroshi; Akiyama, Hideo*; Mochizuki, Hiroki*
Journal of Nuclear Science and Technology, 40(1), p.57 - 60, 2003/01
Times Cited Count:1 Percentile:10.65(Nuclear Science & Technology)Low-level waste (LLW) drums are required to transport as fissile material if the current IAEA's Regulations for the Safe Transport of Radioactive Material are rigorously applied. This problem is a consequence that water contents of concrete in LLW drums contained deuterium (D) in quantities more than 0.1% of fissile material mass, therefore they are not excepted from packages containing fissile material. Consideration of differences in the absorption cross sections of light hydrogen and D shows that the relative increase in the neutron multiplication factor by a presence of D in natural water for hydrogen (H)-moderated systems is not larger than 0.015%. A numerical calculation confirms that the infinite multiplication factor of a mixture of U-metal and water in a
U/H mass ratio of 5% increases proportionally to the D/H atomic ratio, and that its relative increase is less than 0.03% for the D/H atomic ratio of 0.015%. The limiting fissile-to-H mass ratio of 5% in the exception rule is concluded to be applicable to H-moderated systems including D in natural water.
Oishi, Tetsuya; Tsutsumi, Masahiro; Sugita, Takeshi*; Yoshida, Makoto
Proceedings of 1st Asian and Oceanic Congress for Radiation Protection (AOCRP-1) (CD-ROM), 9 Pages, 2002/10
An EGS4 user code has been developed to design gamma ray detection systems for complex shapes of radioactive sources. The code is fundamentally based on the PRESTA-CG, which is improved on the electron transport in the EGS4 and specialized for using a combinatorial geometry (CG) method. The newly added functions are classified mainly into two parts of the transport of particles and the definition of sources. This user code was applied to some detectors used for low-level radioactive wastes monitoring in order to demonstrate the availability of this code. As the result, it was found that the response of anti-Compton spectrometer and the radiation background in a concrete building could be suitably estimated.
Nakamura, Hisashi; Hirabayashi, Takakuni; Akimoto, Jun*; Takahashi, Kenji*; Shindo, Hideaki*; Sakurai, Daihachiro*; Almansour, A.*; Okane, Toshimitsu*; Umeda, Takateru*
Int. J.Cast Metals Res., 11(5), p.339 - 343, 1999/00
Times Cited Count:0 Percentile:0.00(Metallurgy & Metallurgical Engineering)no abstracts in English
E.J.Claude*; Nakamura, Hisashi; D.M.Chapin*; J.W.Simons*; H.Seneviratne*
Proceedings of 7th International Conference on Nuclear Engineering (ICONE-7) (CD-ROM), 10 Pages, 1999/00
no abstracts in English
Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka
JAERI-Review 97-007, 61 Pages, 1997/03
no abstracts in English
Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka
JAERI-Review 96-005, 97 Pages, 1996/03
no abstracts in English
Okoshi, Minoru; Yoshimori, Michiro
Proc. of 3rd Japan-Russia Joint Symp. on Radiation Safety, 0, p.75 - 85, 1995/00
no abstracts in English
Nakamura, Hisashi; Kanazawa, Katsuo; Sato, Takayuki; ; Fujiki, Kazuo
Proc., SPECTRUM 94,Nuclear and Hazardous Waste Management Int. Topical Meeting,Vol. 1, 0, p.206 - 210, 1994/00
no abstracts in English
Fujiki, Kazuo; Hirabayashi, Takakuni; Kanazawa, Katsuo; Yasunaka, Hideo
Waste Management '91, Vol. 1, p.171 - 178, 1991/00
no abstracts in English