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Suzuki, Seiya; Nemoto, Yoshihiro*; Shiiki, Natsumi*; Nakayama, Yoshiko*; Takeguchi, Masaki*
Annalen der Physik, 535(9), p.2300122_1 - 2300122_12, 2023/09
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Urushidate, Tadayuki*; Yoda, Tomoyuki; Otani, Shuichi*; Yamaguchi, Toshio*; Kunii, Nobuaki*; Kuriki, Kazuki*; Fujiwara, Kenso; Niizato, Tadafumi; Kitamura, Akihiro; Iijima, Kazuki
JAEA-Review 2022-023, 8 Pages, 2022/09
JAEA-Review-2022-023.pdf:1.19MB
After the accident of the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency has newly set up a laboratory in Fukushima and started measuring radioactivity concentrations of environmental samples. In October 2015, Fukushima Radiation Measurement Group has been accredited the ISO/IEC 17025 standard by the Japan Accreditation Board (JAB) as a testing laboratory for radioactivity analysis (
Cs, 
Cs) based on Gamma-ray spectrometry with germanium semiconductor detectors. The laboratory has measured approximately 60,000 of various environmental samples at the end of March 2022. The laboratory quality control and measurement techniques have been accredited by regular surveillance of JAB. In September 2019, the laboratory renewed accreditation as a testing laboratory for radioactivity analysis.
spectrometry of terrestrial gamma rays using portable germanium detectors in area of 80 km radius around the Fukushima Daiichi Nuclear Power PlantMikami, Satoshi; Tanaka, Hiroyuki*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Ochi, Kotaro; Uno, Kiichiro*; Matsuda, Norihiro; Saito, Kimiaki
Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(4), p.159 - 178, 2021/12
In order to know the background radiation level where the area affected by the Fukushima Daiichi Nuclear Power Plant accident in 2011, terrestrial gamma rays had been measured by using portable germanium detectors repeatedly from 2013 through 2019, at 370 locations within 80 km radius area centered on the Fukushima Daiichi Nuclear Power Plant. Radioactive concentrations of Uranium 238, Thorium 232, Potassium 40 and kerma rates in air due to terrestrial gamma rays were obtained at those locations based on the method of ICRU report 53. Averaged concentrations of 
U, 
Th and 
K were 18.8, 22.7, 428 Bq/kg, respectively, and kerma rate in air over the area was found to be 0.0402 
Gy/h. The obtained kerma rates in air were compared to those reported in literatures. It was confirmed that the data were correlated with each other, and were agreed within the range of their uncertainty. This is because the kerma rate in air due to terrestrial gamma rays is depend on geology. The similar trend to previous findings was observed that the kerma rate in air at locations geologically classified as Mesozoic era, Granite and Rhyolite were statistically significantly higher than the others.
Kawasaki, Katsuya
Hoken Butsuri, 40(1), p.56 - 60, 2005/03
The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients. This report is introduced about the centralized radioactivity measurement system.
Kawasaki, Katsuya; Mochizuki, Kaoru*; Suzuki, Takehiko; Kinouchi, Nobuyuki
JAERI-Tech 2004-070, 50 Pages, 2004/12
JAERI-Tech-2004-070.pdf:18.19MB
The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients.
Nath, K. G.; Shimoyama, Iwao; Sekiguchi, Tetsuhiro; Baba, Yuji
Journal of Applied Physics, 94(7), p.4583 - 4588, 2003/10
Times Cited Count：15 Percentile：52.13(Physics, Applied)no abstracts in English
Tsutsumi, Masahiro; Oishi, Tetsuya; Kinouchi, Nobuyuki; Sakamoto, Ryuichi; Yoshida, Makoto
Journal of Nuclear Science and Technology, 39(9), p.957 - 963, 2002/09
Times Cited Count：3 Percentile：23.41(Nuclear Science & Technology)An anti-Compton spectrometer with semi-2
Compton suppression is designed to identify the photons emitted from low-level radioactive wastes from radioisotope usage and nuclear research laboratory. Since the objective sample is massive and large, the system has a full opening towards the sample position. The characteristics and features of the system concerning Compton suppression and reduction of the background component due to natural radioactive source are estimated by the Monte Carlo simulations. The anti-Compton technique is shown to be quite advantageous for the reduction of the surrounding natural background radiation, as well as the suppression of the background for the higher energy photons.
detection system in the indoor environments of concrete buildingsTsutsumi, Masahiro; Oishi, Tetsuya; Kinouchi, Nobuyuki; Sakamoto, Ryuichi; Yoshida, Makoto
Journal of Nuclear Science and Technology, 38(12), p.1109 - 1114, 2001/12
In order to predict the indoor background spectra to gamma detection systems, the gamma radiation field in a concrete building is studied by the Monte Carlo simulations. The parameters of wall thickness, room shape and dimensions were considered in the modeling. The indoor source geometry was simulated by a spherical layer model with the intention of easy and effective calculations. The model was applied to an unshielded germanium detector and the detection system with a more complex shielding configuration. As the results, we found that the indoor radiation field in concrete buildings can be predicted well with the source geometry of a spherical concrete layer of 25cm thickness and with the source of the natural major three components of the U series, Th series and K that are homogeneously distributed. The simulation model is useful for designing and optimizing gamma detection systems or shielding assemblies.
Oishi, Tetsuya; Yoshida, Makoto; Saegusa, Jun; Honda, Tetsutaro*; Takahashi, Koji*; Kuwabara, H.*
Journal of Nuclear Science and Technology, 38(3), p.203 - 208, 2001/03
no abstracts in English
Yoshida, Makoto; Oishi, Tetsuya; Saegusa, Jun; Honda, Tetsutaro*; Takahashi, Koji*; Kuwabara, H.*
Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 6 Pages, 2000/05
no abstracts in English
*; Oi, Yoshihiro; Taki, Mitsumasa; Kawasaki, Katsuya; Yoshida, Makoto
Applied Radiation and Isotopes, 50(6), p.1057 - 1061, 1999/00
Times Cited Count：8 Percentile：53.62(Chemistry, Inorganic & Nuclear)no abstracts in English
Toda, Naohiro*; Katayama, Yoshinori; Tsuji, Kazuhiko*
Review of High Pressure Science and Technology, 7, p.647 - 649, 1998/03
The electrical conductivity 
has been measured at pressures 
to 8 GPa and temperatures 
of 77-300K in evaporated amorphous Ge (a-Ge), a-Ge-Cu alloys and a-Ge-Al alloys. The dependence of is well described by a power lw at low temperatures below 150 K, which is expemcted from a multi-phonon tunneling transition process model with weak electron-lattice coupling, rather than the Mott's variable range hopping conduction model. The exponent 
in the power law changes with increasing pressure. For both a-Ge
Cu
and a-GeAl alloys, d(ln )/d show positive values in the low pressure region and negative values in the high pressure region. Results are discussed from several hopping conduction models.
Tanaka, Susumu; Imamura, Mineo*
Genshikaku Kenkyu, 41(3), p.13 - 20, 1996/06
no abstracts in English
Kinoshita, Chiken*; Abe, Hiroaki; *; Fukumoto, Kenichi*
Journal of Nuclear Materials, 219, p.152 - 160, 1995/00
Times Cited Count：13 Percentile：76.19(Materials Science, Multidisciplinary)no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*; *
Mater. Res. Soc. Symp. Proc. Vol. 373, 0, p.487 - 492, 1995/00
no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*
Ionics, 20(7), p.39 - 48, 1994/07
no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*; *; *
Annu. Rep., HVEM LAB., Kyushu Univ., 0(17), p.17 - 18, 1993/00
no abstracts in English
Abe, Hiroaki; Kinoshita, Chiken*; *; *
Proc. Jpn. Acad., Ser. B, 69(7), p.173 - 178, 1993/00
no abstracts in English
Kashihara, Yasuharu*
JAERI-M 91-008, 48 Pages, 1991/02
no abstracts in English
*; *; Matsuda, Koji
Japanese Journal of Applied Physics, 27(9), p.1708 - 1711, 1988/09
Times Cited Count：3 Percentile：23.99(Physics, Applied)no abstracts in English
