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Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Seya, Natsumi; Nishimura, Shusaku; Hosomi, Kenji; Nagaoka, Mika; Yokoyama, Hiroya; Matsubara, Natsumi; et al.
JAEA-Review 2020-069, 163 Pages, 2021/02
JAEA-Review-2020-069.pdf:4.78MB
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 2019 to March 2020. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Maehara, Yushi; Narita, Ryosuke; et al.
JAEA-Review 2019-048, 165 Pages, 2020/03
JAEA-Review-2019-048.pdf:2.69MB
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 2018 to March 2019. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Hokama, Tomonori; Nishimura, Tomohiro; Matsubara, Natsumi; et al.
JAEA-Review 2018-025, 171 Pages, 2019/02
JAEA-Review-2018-025.pdf:3.81MB
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 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Hosomi, Kenji; Nagaoka, Mika; Hokama, Tomonori; Nishimura, Tomohiro; Koike, Yuko; et al.
JAEA-Review 2017-028, 177 Pages, 2018/01
JAEA-Review-2017-028.pdf:3.61MB
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 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Hosomi, Kenji; Nagaoka, Mika; Hokama, Tomonori; Yokoyama, Hiroya; Nishimura, Tomohiro; Matsubara, Natsumi; Maehara, Yushi; et al.
JAEA-Review 2016-035, 179 Pages, 2017/03
JAEA-Review-2016-035.pdf:4.2MB
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 2015 to March 2016. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Takahashi, Satoru*; Okuda, Yasutake*; Kawabata, Kuniaki; Aonuma, Hitoshi*; Sato, Yutaka*; Iwata, Kenji*
Journal of Signal Processing, 20(2), p.65 - 74, 2016/03
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.
Onuma, Yuichi; Tomita, Kenji; Okada, Yuji; Hanawa, Hiroshi
JAEA-Technology 2009-034, 79 Pages, 2009/07
JAEA-Technology-2009-034.pdf:11.23MB
Toward the re-operation of Japan Materials Testing Reactor on 2011 F.Y., the construction of new material irradiation facility for the stress corrosion cracking research under the LWR irradiation environment had been planed, and the design study of water control unit for BWR and water chemical study which supply the LWR simulated water to the material irradiation capsule were carried out on 2007 F.Y. The design study of new material irradiation facility was examined including the reflection of the operation experience and the reuse of components on old material irradiation facility. These examination results were summarized in this report.
Tomita, Kenji; Inoue, Shuichi; Ishida, Takuya; Onuma, Yuichi; Tsuchiya, Kunihiko
JAEA-Technology 2008-050, 41 Pages, 2008/07
JAEA-Technology-2008-050.pdf:6.6MB
Blanket Functional Facility (BFT) for fusion blanket development was established in the Japan Materials Testing Reactor (JMTR). The irradiation tests with Li
TiO
pebble-bed were carried out with the BFT. The BFT was constituted a sweep gas device for tritium measurement and recover and a capsule controlled device for temperature control and neutron flux measurement of LiTiO pebble-bed. Five tritium monitors (ion chambers) for tritium measurement were established in the sweep gas device. In these tritium monitors, one tritium monitor for the measurement of tritium release property (TmIRA201) was not able to be used and it is necessary to exchange new tritium monitors. This report is described the fabrication of new tritium monitors and exchange procedure of this monitors.
Tomita, Kenji; Tsuchiya, Kunihiko; Onuma, Yuichi; Inoue, Shuichi; Watanabe, Hiroyuki; Saito, Takashi; Kikuchi, Taiji; Hayashi, Kimio; Kitajima, Toshio
JAEA-Technology 2008-036, 61 Pages, 2008/06
JAEA-Technology-2008-036.pdf:7.47MB
The second in-situ irradiation experiment using a mock-up (ORIENT-II, JMTR capsule Number: 99M-54J) with a tritium breeder (LiTiO) pebble bed in the Japan Materials Testing Reactor (JMTR) was finished on Aug. 1, 2006. Consideration on the detaching procedure of the irradiated mock-up contaminated with tritium with pebble bed and a detaching test of this mock-up was carried out. The tritium removal properties were examined in the irradiated mock-up, the sweep gas tube, the protective tube and the junction box, for the decreasing of the tritium release to the area of detaching test. Melting/enclosed tests of sealing plug were also carried out for the prevention of tritium leakage from sweep gas lines of pebble bed. Then, the detaching test of the pebble bed was carried out. This report describes the results of tritium removal tests, examination of the detaching procedure, and the detaching test, as well as knowledge obtained from these tests and works.
Hirai, Takashi; Tanai, Kenji; Kikuchi, Hirohito*; Shigeno, Yoshimasa*; Namikawa, Tsutomu*; Takaji, Kazuhiko*; Onuma, Satoshi*
JNC TN8400 2003-034, 158 Pages, 2004/02
JNC-TN8400-2003-034.pdf:5.26MB
The objective of this report is to make a proposal of the proper constitutive models and parameters for the evaluation of the long term mechanical behavior of the buffer material in the engineered barrier system. In the second progress report by JNC, it was reported that the well designed engineered barrier system is stable and safety on mechanical support of the overpack to ensure stability and stress which acts on the overpack by using analysis which based on the popular constitutive models for the general caly soils. However, the buffer material which has swelling characteristics is considered not to be ordinary clay soils. So it is necessary to select the reliable constitutive models again. Therefor the proper models were selected again systematically in the several models which have been used for the assessment of the behavior of clay soils and the simulation analysis on the laboratory tests were carried out by using these models. From the result of the simulation analysis it appeared that the selected two models were alike to assess the behavior of the buffer material and the parameters which need to simulate the consolidation tests are different from those for the triaxial compression tests. Finally the analysis was conducted to evaluate the effect of the swelling of the overpack by the collosion and the self weight which causes the sedimentation of the overpack. From the analytical result, it was clarified that two kinds of parameter sets are necessary to evaluate the deformation and the stress of the buffer material in the engineered barrier system.
Hirai, Takashi; Tanai, Kenji; Kikuchi, Hirohito*; Takaji, Kazuhiko*; Onuma, Satoshi*
JNC TN8400 2003-031, 48 Pages, 2004/02
JNC-TN8400-2003-031.pdf:2.22MB
The objective of this report is to clarify the characteristics of the bearing capacity of the buffer material against the deformation of the overpack in the engineered barrier system. In the second progress report by JNC, it was reported that the well designed engineered barrier system is stable and safety on mechanical support of the overpack to ensure stability and stress which acts on the overpack by some analysis. However, the degree of the capacity to the ultimate state and the background datas of the design are not necessary clarified in the report. Therefore it is considered to be mportant to assess the ultimate state and make the relationship clear between deformation and bearing capacity of the overpack in the engineered barrier system. So the scale test and the simulation analysis were carried out for the longitudinal deformation of the overpack in the saturated buffer material constrained by the host rock. From the result of the scale test and the analysis it appears that the bearing capacity is increasing with the deformation of the overpack even if the bearing capacity is over the yielding force and the relationship between deformation and bearing capacity can be approximately expressed by the simple fanction.
Hirai, Takashi; Tanai, Kenji; Kikuchi, Hirohito*; Suzuki, Hideaki*; *; Onuma, Satoshi*
JNC TN8400 2003-009, 56 Pages, 2003/03
JNC-TN8400-2003-009.pdf:7.22MB
The objective of this report is to clarify mechanical effect of engineered barrier system to the unavoidable fault movement. From the basic policy of the second progess report by JNC, natural phenomenon which affect strongly to the geological disposal system shoult be avoided. However, small faults as sliprate "C" far from principal fault zone, are difficult to be found out completely. Therefore, it is important to evaluate the influence of these fault movements and to clarify stability and safety of the engineered barrier system. Accordingly, the effect of a rock displacement across a deposition holl was considered and the midium scale test was carried out. Then midium scale test was simulated by Finit Element Method in which the constitutive model of Tresca was adopted to analyze elastoplastic behavior of buffer material. From the result of the midium scale test and the analysis, it was realized that the buffer material diminish shear stress acting on the overpack. Further analytical study was conducted to evaluate the real scale engineered barrier system designed in the second progress report by JNC. From the study, it was apeared that stress in buffer corresponded to the stress calculated for the midium scale test model. Consequently, it was obvious that rock displacement, 80% of buffer thickness, didn't affect overpack if velocity of fault movement was under 10 cm/sec.
Katakai, Akio; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Seko, Noriaki; Kawabata, Yukiya*; Onuma, Kenji*; Takeda, Hayato*; Sugo, Takanobu
JAERI-Tech 2002-040, 79 Pages, 2002/03
JAERI-Tech-2002-040.pdf:8.62MB
The present report dealt with experimental methods of adsorbents synthesis, recovery, elution, analysis in experimental equipment for recovery of rare metals from seawater to evaluate performance of the adsorbent synthesized by radiation-induced graft-polymerization. In the adsorbent synthesis, monomers of acrylonitrile and methacryl acid were continuously co-grafted into polymer nonwoven fabric irradiated with electron beam. The grafted nonwoven fabric was amidoximated and treated with alkaline solution in batch processing. The obtained adsorbent fabrics which were cut into 116 sheets of the square, 160 mm 
290 mm, were alternatively stacked with spacers to make an adsorbent cassette. In recovery process, a large-sized cage packing 144 pieces of the adsorbent cassette was dipped into sea in the depth of 20 m by using an experimental marine equipment. In the case of a small-sized cage, there are 36 adsorbent cassettes in it. In elution step, first, marine animals which were adhered on the adsorbent cassette were washed out immediately after the adsorbent cassettes were recovered from sea. From every 72 adsorbent cassettes packed into elution unit, second, alkaline and rare metals were fractionally eluted by changing acid concentration in fractional elution equipment. The eluted metals were adsorbed onto a commercial chelate resin to transport them to purificatory factory. Concentrations of metals in eluent and waste solution were analyzed with inducticely coupled plasma atomic emission and mass spectrometry (ICP-AES and ICP-MS). The rare metal distribution in the adsorbent was evaluated by using the same analytical methods.
Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Hasegawa, Shin; Kawabata, Yukiya*; Onuma, Kenji*; Takeda, Hayato*; Katakai, Akio; Sugo, Takanobu
JAERI-Tech 2001-065, 39 Pages, 2001/11
JAERI-Tech-2001-065.pdf:5.24MB
Positioning and monitoring system for marine component in recovery equipment of significant metals from seawater by using adsorbent was designed and assembled to avoid unexpected accidents. This system which was set on float part of the marine component obtains the position data by means of GPS satellites and send them to Takasaki and Mutsu establishments through satellite communication. As characteristic test for 20 days in the real sea, 256 data were obtained every 2 hours. The wrong data was eight and the positioning accuracy was 200.7m. To improve these characteristics, two new functions were added to the present firmware. These are to raise positioning resolutions in longitude and latitude from 0.001 to 0.00001 degree and to average remaining three data of positioning after maximum and minimum data were removed from continuous five times positioning. The improved system shows no wrong datum, average positioning of 6.74m. This performance is enough to prevent marine equipment from its drifting accident.
Takeda, Hayato*; Onuma, Kenji*; Tamada, Masao; Kasai, Noboru; Katakai, Akio; Hasegawa, Shin; Seko, Noriaki; Kawabata, Yukiya*; Sugo, Takanobu
JAERI-Tech 2001-062, 66 Pages, 2001/10
Real sea experiment for the recovery of significant metals such as uranium and vanadium has been carried out at the offing of Mutsu establishment to evaluate the adsorption performance of adsorbent synthesized by radiation-induced graft-polymerization. After elution of uranium and vanadium from the adsorbent, their metals were adsorbed onto the conventional chelate resin. This chelate resin in a plastic column was further put in a cylindrical stainless transport container. The container was transported to the facility for separation and purification by a truck for the exclusive loading. The maximum concentration is 60 Bq/g when the uranium is adsorbed on the chelate resin. Transportation of recovered metals can be treated as general substance since these amount and concentration are out of legal control. However, the recovered metals were transported in conformity to L type transportation as a voluntary regulation. The strength analysis of the container was equal to the safety level of IP-2 type which is higher transportation grade than L type .
Maki, Yasuro*; Kitano, Koichi*; Inoue, Daiei*; Onuma, Hiroshi*; Komada, Hiroya*; Yamaji, Kenji*; Osumi, Takashi*; Tanaka, Hiroshi*; Imazu, Masanori*
JNC TJ1400 2005-005, 98 Pages, 1989/03
JNC-TJ1400-2005-005.pdf:2.98MB
no abstracts in English
Onuma, Isamu; Kanamori, Kenji; Sekijima, Mitsuaki; Kobayashi, Makoto; Akiyama, Isamu; Shimizu, Isamu
no journal, ,
no abstracts in English
