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Abe, Takeyasu; Iida, Yoshihisa; Sasamoto, Hiroshi; Ishii, Eiichi
Proceedings of Water-Rock Interaction (WRI-17)/ Applied Isotope Geochemistry (AIG-14), 6 Pages, 2023/08
Cation exchange is one of important elementary reactions among water-rock interactions in sedimentary rocks. In order to model non-constant Na-K-Ca-Mg-H exchange selectivity of sedimentary rocks, exchange isotherms and pH dependence on cation exchange capacity of smectite were analyzed following active fraction model. As the result of comparison of exchangeable cationic composition between measured and calculated, selectivity coefficients determined in this study were preferred to those presented by previous studies. Using the coefficients and groundwater hydrochemistry reported previously, expected compositions of exchangeable cations were calculated. The results suggested that pH and total Na-K-Ca-Mg-H concentration of groundwater are important factors to interpret observed compositional variation in exchangeable base cations.
Ohira, Saki; Abe, Takeyasu; Iida, Yoshihisa
Radiochimica Acta, 111(7), p.525 - 531, 2023/07
Times Cited Count：0 Percentile：0.00(Chemistry, Inorganic & Nuclear)The solubility of 
Nb in calcium alkaline solutions is one of the important parameters in safety assessment of intermediate-depth disposal which are assumed to use cementitious materials. Nb solubility and solubility-limiting solid phases of Nb in these systems remain unclear. The oversaturation solubility experiments were performed systematically in the 0.001-0.1 M CaCl
solutions under alkali conditions, and the characterization of precipitated solid phase controlling Nb solubility was conducted. The negative dependence of Nb solubilities on pH and Ca concentration was observed in solubility experiments, the molar ratio of Nb to Ca of precipitated solid phase was 0.66. The pH and Ca dependence of Nb solubilities was reproduced by the reaction with Nb aqueous species Nb(OH)
and Ca-Nb oxide with the molar ratio of Nb to Ca 0.66, e.g., Ca
NbO
(am).
Abe, Takeyasu; Iida, Yoshihisa
Journal of Advanced Concrete Technology, 20(3), p.236 - 253, 2022/03
Times Cited Count：3 Percentile：10.21(Construction & Building Technology)This paper is a state-of-the-art report on the performance assessment of cementitious and related materials as components of engineered barrier systems for radioactive waste management. In this paper, (1) the concept of safety functions is reviewed as the engineering background of discussion, (2) an overview of the postclosure performance assessment for Belgian low- and intermediate-level short-lived radioactive waste disposal is provided, and (3) a modeling methodology for engineered barrier systems is analyzed using the concept of "mandala for durability mechanics". According to these works, authors present technical suggestions for technical stakeholders of Japanese low-level radioactive waste disposal.
Abe, Takeyasu; Kuribayashi, Takahiro*; Nakamura, Michihiko*
European Journal of Mineralogy, 29(6), p.949 - 957, 2017/12
Times Cited Count：3 Percentile：8.78(Mineralogy)Polarised infrared spectra of synthetic single crystals and radiation-damaged natural samples were collected to examine hydroxyl incorporation in monazite. The IR spectra of pure synthetic monazite contain two OH stretching bands at 3163 and 3335 cm
with contrasting bandwidths of 40 and 90 cm, respectively. The two OH bands show strong pleochroism and dominant infrared absorption in the Y direction. The IR spectra of natural monazite contains a weak pleochroic OH band centered around 3400 cm with a bandwidth of more than 200 cm. During step-heating experiments, this broad OH band split into several bands, and these bands differ from those observed in the spectra of synthetic samples. The OH stretching signals in the spectra of both natural and synthetic samples disappeared after heating at 1000
C. Based on these results, OH defects in natural monazite arise because of secondary hydration facilitated by radiation damage, as in the case of natural zircon and xenotime.
Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Takeyasu, Masanori; Mizutani, Tomoko; Isozaki, Tokuju*; Nagaoka, Mika; Hokama, Tomonori; Yokoyama, Hiroya; Nishimura, Tomohiro; et al.
JAEA-Review 2015-034, 175 Pages, 2016/03
JAEA-Review-2015-034.pdf:8.13MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2014 to March 2015. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co. in March 2011.
Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Takeyasu, Masanori; Mizutani, Tomoko; Isozaki, Tokuju; Morisawa, Masato; Nagaoka, Mika; Hokama, Tomonori; Yokoyama, Hiroya; et al.
JAEA-Review 2014-042, 175 Pages, 2015/01
JAEA-Review-2014-042.pdf:10.89MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2013 to March 2014. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Co. in March 2011.
Sumiya, Shuichi; Watanabe, Hitoshi; Miyagawa, Naoto; Nakano, Masanao; Nakada, Akira; Fujita, Hiroki; Takeyasu, Masanori; Isozaki, Tokuju; Morisawa, Masato; Mizutani, Tomoko; et al.
JAEA-Review 2013-056, 181 Pages, 2014/03
JAEA-Review-2013-056.pdf:6.22MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2012 to March 2013. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Co. in March 2011.
Sumiya, Shuichi; Watanabe, Hitoshi; Nakano, Masanao; Takeyasu, Masanori; Nakada, Akira; Fujita, Hiroki; Isozaki, Tokuju; Morisawa, Masato; Mizutani, Tomoko; Nagaoka, Mika; et al.
JAEA-Review 2013-009, 195 Pages, 2013/06
JAEA-Review-2013-009.pdf:3.35MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2011 to March 2012. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Plant on Tokyo Electric Power Co. in March 2011.
Sumiya, Shuichi; Watanabe, Hitoshi; Nakano, Masanao; Takeyasu, Masanori; Nakada, Akira; Fujita, Hiroki; Isozaki, Tokuju; Morisawa, Masato; Mizutani, Tomoko; Kokubun, Yuji; et al.
JAEA-Review 2012-015, 166 Pages, 2012/05
JAEA-Review-2012-015.pdf:3.53MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2010 to March 2011. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Plant on Tokyo Electric Power Co. in 2011 March. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data exceeded the normal range of fluctuation by the accidental release was evaluated in the appendices.
Takeyasu, Masanori; Nakano, Masanao; Fujita, Hiroki; Nakada, Akira; Watanabe, Hitoshi; Sumiya, Shuichi; Furuta, Sadaaki
Journal of Nuclear Science and Technology, 49(3), p.281 - 286, 2012/03
Times Cited Count：25 Percentile：84.67(Nuclear Science & Technology)As a response to the Fukushima Daiichi Nuclear Power Plant accident, emergency environmental radiation monitoring was performed at the Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency (JAEA). This paper provisionally describes the results of the monitoring including ambient radiation dose rate and radioactivity concentrations in airborne and fallout. The ambient radiation dose rate began to increase since about 1:00 on March 15 2011, and varied with three peak dose rate of several thousand 
Gy/h at 8:00 on March 15, at 5:00 on March 16, and at 4:00 on March 21. The variation over time in radioactivity concentrations in airborne and fallout almost showed the same tendency as that of the dose rate. The fallout of 
Cs for 1 month from March 15 to April 15 was about 120 times higher than that in May 1986 after the Chernobyl accident. The internal dose by inhalation was estimated from the airborne concentration observed.
Furuta, Sadaaki; Sumiya, Shuichi; Watanabe, Hitoshi; Nakano, Masanao; Imaizumi, Kenji; Takeyasu, Masanori; Nakada, Akira; Fujita, Hiroki; Mizutani, Tomoko; Morisawa, Masato; et al.
JAEA-Review 2011-035, 89 Pages, 2011/08
JAEA-Review-2011-035.pdf:2.97MB
As a correspondence to the accident at the Fukushima Daiichi Nuclear Power Plant, the environmental radiation monitoring was performed at the Nuclear Fuel Cycle Engineering Laboratories, JAEA. This report presented the measurement results of ambient radiation dose rate, radioactivity concentration in the air and radioactivity concentration in fallout and meteorological observation result until May 31, 2011. The ambient radiation dose rate increased, with the peak dose rate of several thousand nGy/h at 7 o'clock in March 15, at 5 o'clock in March 16, and at 4 o'clock in March 21. The variation on the radioactivity concentration in the air and in fallout showed the almost same tendency as that of the dose rate. The concentration ratio of I-131/Cs-137 in the air increased to about 100. The dose was estimated resulting from internal exposure due to inhalation.
Sumiya, Shuichi; Matsuura, Kenichi; Watanabe, Hitoshi; Nakano, Masanao; Takeyasu, Masanori; Fujita, Hiroki; Isozaki, Tokuju; Morisawa, Masato; Mizutani, Tomoko; Kokubun, Yuji; et al.
JAEA-Review 2011-004, 161 Pages, 2011/03
JAEA-Review-2011-004.pdf:4.09MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2009 to March 2010. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes.
-ray dose rate around the Nuclear Fuel Cycle Engineering Laboratories, JAEAMizutani, Tomoko; Onuma, Toshimitsu; Sugai, Masamitsu*; Watanabe, Hajime*; Morisawa, Masato; Takeyasu, Masanori; Sumiya, Shuichi
Progress in Nuclear Science and Technology (Internet), 1, p.380 - 383, 2011/02
The Nuclear Fuel Cycle Engineering Laboratories (NCL), JAEA operates the Tokai Reprocessing Plant (TRP), plutonium fuel fabrication facilities and the supplemental facilities. In the terrestrial environment, environmental -ray dose rate was measured continuously using an energy-thermo-compensation-type NaI(Tl) scintillation counter. The data of environmental dose rate measured in 5 monitoring stations and 8 monitoring posts were collected and analyzed to monitor on real-time. This paper summarizes the monitoring data of environmental dose rate around the NCL during the past 10 year (fiscal 1998-2007). The monthly average of the environmental dose rate for all monitoring stations and posts were in the range of 31-48 nGy h, except the value influenced by the criticality accident at the JCO in 1999. The long-term variation in the environmental dose rate was not found. The cases of the short-term increases occurred by the operations of the facilities in the NCL were concluded by the discharges of 
Kr from the TRP, transportation of MOX fuels or radioactive solid wastes, X-ray generator to calibrate the radiation monitoring instruments. The other cases to affect the change of the environmental dose rate were the scavenging of the airborne natural radionuclides, a patient cured by the radiation therapy and the shield effect by cars.
Sumiya, Shuichi; Matsuura, Kenichi; Nakano, Masanao; Takeyasu, Masanori; Morisawa, Masato; Onuma, Toshimitsu; Fujita, Hiroki; Mizutani, Tomoko; Watanabe, Hajime*; Sugai, Masamitsu*
JAEA-Review 2009-064, 166 Pages, 2010/03
JAEA-Review-2009-064.pdf:11.08MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been conducted by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of JAEA, Chapter IV; Environmental monitoring" and Environmental Radiation Monitoring Program decided by the Ibaraki prefectural government. The radiation monitoring installations and equipments were also prepared for emergency. This manual describes; (1) the installations of radiological measurement, (2) the installations of meteorological observation, and (3) environmental data processing system for executing the terrestrial environmental monitoring by Environmental Protection Section, Radiation Protection Department. The environmental monitoring has been operated through the manual published in 1993 (PNC TN8520 93-001). Then the whole articles were revised because the partially of installations and equipments having been updated in recent years.
Takeishi, Minoru; Sumiya, Shuichi; Matsuura, Kenichi; Watanabe, Hitoshi; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki*; Isozaki, Tokuju; Morisawa, Masato; Fujita, Hiroki; et al.
JAEA-Review 2009-048, 177 Pages, 2009/12
JAEA-Review-2009-048.pdf:19.3MBJAEA-Review-2009-048(errata).pdf:0.12MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV; Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2008 to March 2009. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes.
Takeishi, Minoru; Matsuura, Kenichi; Watanabe, Hitoshi; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki; Isozaki, Tokuju; Morisawa, Masato; Fujita, Hiroki; Kokubun, Yuji; et al.
JAEA-Review 2008-057, 155 Pages, 2008/11
JAEA-Review-2008-057.pdf:2.15MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of JAEA, Chapter IV; Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged to the atmosphere and the sea during April 2007 to March 2008. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and its trends, meteorological data and discharged radioactive wastes.
Takeishi, Minoru; Miyagawa, Naoto; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki; Isozaki, Tokuju; Morisawa, Masato; Fujita, Hiroki; Kokubun, Yuji; Kato, Chiaki; et al.
JAEA-Review 2007-044, 155 Pages, 2008/02
JAEA-Review-2007-044.pdf:2.58MBJAEA-Review-2007-044(errata).pdf:0.13MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of JAEA, Chapter 4; Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged to the atmosphere and the sea during April 2006 to March 2007. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and its trends, meteorological data and discharged radioactive wastes.
Kr from a reprocessing plant over a coastal area; Performance examination of an emergency environmental radiation dose evaluation code system "SIERRA-II"Takeyasu, Masanori; Iida, Takao*; Watanabe, Hitoshi; Takeishi, Minoru; Yamamoto, Asao*
Journal of Radioanalytical and Nuclear Chemistry, 275(1), p.43 - 54, 2008/01
Times Cited Count：1 Percentile：9.84(Chemistry, Analytical)The performance of the computer code system "SIERRA-II" for calculating the environmental radiation dose due to an accident was assessed using the environmental monitoring data around the coastally located Tokai Reprocessing Plant (TRP) when Kr was discharged during its operation. The agreement within a factor of 5 between the calculated and observed air concentrations of Kr in areas of a few km from the TRP was achieved in 57% of the comparison data, and the agreement within a factor of 2 was obtained in 29%, disregarding the internal boundary layer. According to the vertical profile of atmospheric temperatures, the internal boundary layer was modeled in the SIERRA-II and the agreement became better than when the internal boundary layer was not considered.
Takeishi, Minoru; Miyagawa, Naoto; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki; Isozaki, Tokuju; Morisawa, Masato; Fujita, Hiroki; Kokubun, Yuji; Kato, Chiaki; et al.
JAEA-Review 2006-031, 155 Pages, 2006/10
JAEA-Review-2006-031.pdf:7.76MBJAEA-Review-2006-031(errata).pdf:0.13MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of JAEA, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged to the atmosphere and the sea during April 2005 to March 2006. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and its trends, meteorological data and discharged radioactive wastes.
Takeishi, Minoru; Naoto, Miyagawa,; Hitoshi, Watanabe,; Uezu, Yasuhiro; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki
JNC TN8440 2004-002, 149 Pages, 2004/06
JNC-TN8440-2004-002.pdf:3.78MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed since 1975, based on "Safety Regulations for the Tokai Reprocessing Plant, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant during April 2003 to March 2004. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant.
