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Nagaoka, Mika; Yokoyama, Hiroya; Fujita, Hiroki; Nakano, Masanao; Watanabe, Hitoshi; Sumiya, Shuichi
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1305 - 1308, 2015/02
Times Cited Count:17 Percentile:78.95(Chemistry, Analytical)Various kinds of radionuclides were released into the atmosphere and the sea from the Fukushima Daiichi Nuclear Power Plant on Tokyo Electric Power Co. (TEPCO) by the accident and then reached around our laboratories. Therefore the accident influence on our environment was investigated to measure the concentrations of cesium-134 (Cs), cesium-137
Cs, strontium-90 (
Sr) and plutonium isotopes in seabed sediments. The values for
Cs ranged from 6.1 to 300 Bq/kg (dry wt) and the ratio of
Cs /
Cs ranged from 0.48 to 0.77. The highest point of
Cs concentration was observed at the northernmost station near Kitaibaraki City and the concentration was similar to report by MEXT.
Ishimatsu, Naoki*; Sata,Yusuke*; Maruyama, Hiroshi*; Watanuki, Tetsu; Kawamura, Naomi*; Mizumaki, Masaichiro*; Irifune, Tetsuo*; Sumiya, Hitoshi*
Hoshako, 28(1), p.3 - 11, 2015/01
no abstracts in English
Nagaoka, Mika; Yokoyama, Hiroya; Fujita, Hiroki; Nakano, Masanao; Watanabe, Hitoshi; Sumiya, Shuichi
KEK Proceedings 2014-7, p.194 - 200, 2014/11
no abstracts in English
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
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; Miyagawa, Naoto; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki; Otani, Kazunori*; Hiyama, Yoshinori*; et al.
JAEA-Review 2013-041, 115 Pages, 2014/01
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2012, from 1st April 2012 to 31st March 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Nagaoka, Mika; Fujita, Hiroki; Nakano, Masanao; Watanabe, Hitoshi; Sumiya, Shuichi
Hoken Butsuri, 48(4), p.165 - 166, 2013/12
no abstracts in English
Nakano, Masanao; Watanabe, Hitoshi; Sumiya, Shuichi
JAEA-Testing 2013-003, 29 Pages, 2013/11
Since the remote sensing technique for the meteorological observation has been developing these years, the Doppler Lidar is available in the commercial market. Although some investigation organization carried out the examination on the method and application of Doppler Lidars and had generally good results, the duration of the examination was limited in a short period. So it is unknown that the Doppler Lidar can be applicable to the long-term meteorological observation in the nuclear facilities to assess the public dose around nuclear facilities. In order to examine the long-term performance requested by the Japanese guideline for meteorological observation (i.e., the annual and the sequential 30-days missing rate should be less than 10% and 30%, respectively.) and the consistency with the data measured by conventional type, the wind direction and speed was measured by the Doppler Lidar (Windcube WLS7 made by Leosphere Co Ltd.) for one year, then compared with those by the propeller type installed at the top of the meteorological observation tower. As the result, the missing rate of the Doppler Lidar was satisfied with the guideline at the height less than 180 m, and the data at 68 m above the ground level (100 m above sea level) had a good relationship with the propeller data. From this fact, the Doppler Lidar used in this examination is considered to have a practicability for the dose assessment of the public.
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
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.
Nagaoka, Mika; Fujita, Hiroki; Nakano, Masanao; Watanabe, Hitoshi; Sumiya, Shuichi
Hoken Butsuri, 48(2), p.104 - 113, 2013/06
Monthly deposition samples were collected in the NCL which is located at about 115km south of the Fukushima Daiichi NPP, and the radioactive nuclides were analyzed. Although radionuclides such as I (T
=8.02 days),
Te-
Te (T
=33.6 days) and
Te-
I (T
=3.2 days) with
Cs and
Cs were observed by
spectrometry at the early time of the Fukushima Daiichi NPP accident, only
Cs and
Cs were detected as of September 2012. The annual deposition of
Cs and
Cs were about 19,000 and 17,000 Bq/m
, respectively in March 2011 - February 2012 after the accident. Moreover,
Sr was detected in some samples. Monthly
Sr deposition in March 2011 was 5.1 Bq/m
month and then decreased after that. On the other hand,
Pu concentration was the same level with the concentration before the accident.
Sumiya, Shuichi; Watanabe, Hitoshi; Miyagawa, Naoto; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Hiyama, Yoshinori; Yoshii, Hideki*; Otani, Kazunori*; Goto, Ichiro*; et al.
JAEA-Review 2013-005, 116 Pages, 2013/05
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2011, from 1st April 2011 to 31st March 2012. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Nagaoka, Mika; Nakano, Masanao; Fujita, Hiroki; Watanabe, Hitoshi; Sumiya, Shuichi
Dai-55-Kai Kankyo Hoshano Chosa Kenkyu Seika Rombun Shorokushu (Heisei-23-Nendo), p.7 - 8, 2013/03
no abstracts in English
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
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.
Sumiya, Shuichi; Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Hiyama, Yoshinori; Yoshii, Hideki*; Kikuchi, Masaaki*; Otani, Kazunori*; Goto, Ichiro*
JAEA-Review 2012-006, 114 Pages, 2012/03
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2010, from 1st April 2010 to 31st March 2011. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
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:84.60(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
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
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.
Sumiya, Shuichi; Matsuura, Kenichi; Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Hiyama, Yoshinori; Yoshii, Hideki*; Fujii, Jun*; Kikuchi, Masaaki*; et al.
JAEA-Review 2010-072, 115 Pages, 2011/02
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2009, from 1st April 2009 to 31st March 2010. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Koarashi, Jun; Fujita, Hiroki; Watanabe, Hitoshi; Sumiya, Shuichi
Journal of Nuclear Science and Technology, 48(1), p.120 - 129, 2011/01
Times Cited Count:7 Percentile:47.38(Nuclear Science & Technology)Carbon-14 (C) is of great interest in dose assessment due to the nuclear industry. We collected terrestrial environmental samples at various locations at different time intervals around the Tokai Reprocessing Plant (TRP), and measured their
C concentrations. The results consistently gave the picture of
C dispersion pattern that the prevailing wind conveyed
C plume, and as a result caused elevated
C concentrations in the area 2-3 km southwest of the main stack. The
C increases were however quite temporary. The
C concentrations in vegetations generally followed those in atmospheric CO
, but seemed different in the integrated period of reflecting the atmospheric
C level between vegetations. We found the highest
C concentration of 374 Bq/kg-C
. The annual effective dose due to
C was estimated to be only 0.07% of the annual effective dose limit. Thus, we conclude that the
C releases from the TRP have a very slight impact both on the environment and on the public.
Nakano, Masanao; Hiyama, Yoshinori; Watanabe, Hitoshi; Sumiya, Shuichi
Radioisotopes, 59(5), p.319 - 328, 2010/05
The rapid analysis method of Sr and
Sr in effluent has been investigated by a liquid scintillation counter, which could distinguish the difference of beta energy. Analyzed the imitation effluent samples including interference radionuclides such as
Mn,
Co,
Ru,
Cs, the good accuracy, precision and chemical recovery were obtained in the analyses. It took only 3 or 4 days to analyze them by this method, though it took a few weeks by the conventional methods. These facts made it sure that this method was worth enough for the analysis of
Sr and
Sr in effluent.
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
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.