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JAEA Reports

Analysis of the radioactivity concentrations in radioactive waste generated from JPDR Facility

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

JAEA-Data-Code-2021-013.pdf:1.47MB

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 ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{41}$$Ca, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{rm 108m}$$Ag, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{rm 166m}$$Ho, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239}$$Pu, $$^{240}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.

JAEA Reports

Study on the radioactivity evaluation method of biological shielding concrete of JPDR for near surface disposal

Kochiyama, Mami; Okada, Shota; Sakai, Akihiro

JAEA-Technology 2021-010, 61 Pages, 2021/07

JAEA-Technology-2021-010.pdf:3.56MB
JAEA-Technology-2021-010(errata).pdf:0.75MB

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.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from JRR-3 and JPDR facilities

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

JAEA-Data-Code-2020-022.pdf:1.74MB

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($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{41}$$Ca, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{rm 108m}$$Ag, $$^{133}$$Ba, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{rm 166m}$$Ho, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239+240}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of the samples.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from JPDR and JRR-4

Aono, Ryuji; Mitsukai, Akina; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2020-006, 70 Pages, 2020/08

JAEA-Data-Code-2020-006.pdf:2.59MB

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 ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{99}$$Tc, $$^{rm 108m}$$Ag, $$^{129}$$I, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239+240}$$Pu, $$^{241}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of those samples.

Journal Articles

Development of automated measurement device for low-level radioactive contamination on building surfaces

Tachibana, Mitsuo; Ito, Hirokuni*; Hatakeyama, Mutsuo*; Yanagihara, Satoshi

Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(1), p.120 - 127, 2004/03

The RAPID-1600 was developed to measure a low-level radioactive contamination on building surfaces automatically. The double layered detectors are structured by two gas flow type detectors with a $$beta$$ rays shielding plate between the two detectors and it is horizontally positioned. The lower counter measures $$beta$$ and $$gamma$$ rays and the upper counter measures $$gamma$$ rays. The $$beta$$ rays counting rates are derived by subtracting $$gamma$$ rays counting rates of the upper counter from $$gamma$$ and $$beta$$ rays counting rates of the lower counter. This mechanism results in sensitive to $$beta$$ rays against to low background radiation conditions. The driving unit can move omnidirectionally by controlling two driving wheels individually, and has a capability to correct its position if an orbital error is detected by the self-position identification system. The RAPID-1600 was successfully applied to the actual measurement in the radioisotope production facilities. The RAPID-1600 is expected to be a useful tool for measurement of radioactivity in decommissioning nuclear facilities.

JAEA Reports

Development of measuring device for inner surfaces of embedded piping (Contract research)

Ito, Hirokuni*; Hatakeyama, Mutsuo*; Tachibana, Mitsuo; Yanagihara, Satoshi

JAERI-Tech 2003-012, 34 Pages, 2003/03

JAERI-Tech-2003-012.pdf:2.87MB

The MISE was developed to evaluate low-level radiological contaminations of inner surfaces of piping. The MISE consists of a cylindrically-formed double layered type detector and a piping crawling robot, which were designed and manufactured separately. In measurements of the contaminations, an outer cylindrical detector close to the surface of piping measures $$beta$$-rays and $$gamma$$-rays and an inner cylindrical detector set after a shielding plate for shield of $$beta$$-rays measures $$gamma$$-rays. The $$beta$$-ray counting rates are derived by subtracting $$gamma$$-ray counts measured by the inner detector from $$gamma$$- and $$beta$$-ray counts measured by the outer detector. The robot transports the double layered type detector with observing inner surfaces of piping. The detection limit for the contamination of $$^{60}$$Co was found to be about 0.17Bq/cm$$^{2}$$ with measurement time of 30 seconds. It is expected that 0.2Bq/cm$$^{2}$$ corresponding to clearance level of $$^{60}$$Co (0.4Bq/g) can be evaluated with measurement time of 2 seconds, which is equal to measurement speed of 54m/h.

JAEA Reports

Study on disposal method of graphite blocks and storage of spent fuel for modular gas-cooled reactor (Joint research)

Sumita, Junya; Sawa, Kazuhiro; Tsuchie, Yasuo*; Urakami, Masao*; Kunitomi, Kazuhiko

JAERI-Tech 2002-104, 23 Pages, 2003/02

JAERI-Tech-2002-104.pdf:1.15MB

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.

Journal Articles

Deuterium effect on the subcritical limit for fissile-to-hydrogen ratio

Okuno, Hiroshi; Akiyama, Hideo*; Mochizuki, Hiroki*

Journal of Nuclear Science and Technology, 40(1), p.57 - 60, 2003/01

 Times Cited Count:1 Percentile:11.39(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 $$^{235}$$U-metal and water in a $$^{235}$$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.

Journal Articles

An EGS4 user code for designing $$gamma$$ ray detection systems

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.

Journal Articles

An Investigation of steel plate-cast iron hybrid casting process for recycling of low level radioactive metal waste

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:0.01(Metallurgy & Metallurgical Engineering)

no abstracts in English

Journal Articles

Update on decommissioning waste from nuclear power plants

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

JAEA Reports

Progress report on safety research on radioactive waste management for the period April 1995 to March 1996

Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka

JAERI-Review 97-007, 61 Pages, 1997/03

JAERI-Review-97-007.pdf:2.18MB

no abstracts in English

JAEA Reports

Progress report on safety research on radioactive waste management for the period April 1993 to March 1995

Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka

JAERI-Review 96-005, 97 Pages, 1996/03

JAERI-Review-96-005.pdf:2.88MB

no abstracts in English

Journal Articles

Near surface disposal of VLLW from reactor decommissioning and safety requirements

Okoshi, Minoru; Yoshimori, Michiro

Proc. of 3rd Japan-Russia Joint Symp. on Radiation Safety, 0, p.75 - 85, 1995/00

no abstracts in English

Journal Articles

Fundamental research on melting of radioactive metal materials

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

Journal Articles

Decontamination and melting test for metal wastes in JPDR decommissioning project; Toward recycling of LLW

Fujiki, Kazuo; Hirabayashi, Takakuni; Kanazawa, Katsuo; Yasunaka, Hideo

Waste Management '91, Vol. 1, p.171 - 178, 1991/00

no abstracts in English

Journal Articles

Low-level radioactivity measurement methods for reusing or recycling

; ;

EPA-520/1-90-013, p.82 - 89, 1990/00

no abstracts in English

Journal Articles

Development of reactor decommissioning technoloogy in JAERI; Radiation control

;

Genshiryoku Kogyo, 32(9), p.70 - 74, 1986/09

no abstracts in English

Journal Articles

Removal of radionuclides of transitional of metal elements from low-level liquid waste by electrolytic floatation method

; *; *;

Radioact.Waste Manage.Nucl.Fuel Cycle, 3(1), p.17 - 27, 1982/00

no abstracts in English

Journal Articles

A Spectrometric method for measurement of low-level $$gamma$$ exposure dose

; Miyanaga, Ichiro

Health Physics, 12(4), p.541 - 551, 1966/00

 Times Cited Count:41

no abstracts in English

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