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Mikami, Satoshi; Ishikawa, Daisuke*; Matsuda, Hideo*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Saito, Kimiaki
Journal of Environmental Radioactivity, 210, p.105938_1 - 105938_7, 2019/12
Times Cited Count:3 Percentile:10.43(Environmental Sciences)Five intercomparisons of in situ spectrometry by 6-7 participating teams have been conducted between December 2011 and August 2015 at sites in Fukushima prefecture which affected by the fallout of FDNPS accident occurred in March 2011. The evaluated deposition densities agreed within 5-6% in terms of coefficient of variation (CV) for radiocesium (
Cs and
Cs), by our best achievement, and the ratio of
Cs/
Cs in deposition density agreed within 1-2% in CV, through five intercomparisons. These results guarantee the accuracy of the measurements of the mapping project. Two different methods for intercomparison were conducted: (1) sequential measurements at an identical point; and (2) simultaneous measurements in a narrow area within 3 m radius. In a comparison between the two methods at a site, no significant difference was observed between the results. The standard protocols for the two different intercomparison methods were proposed based on our experience.
Iwasaki, Toshiki*; Sekiyama, Tsuyoshi*; Nakajima, Teruyuki*; Watanabe, Akira*; Suzuki, Yasushi*; Kondo, Hiroaki*; Morino, Yu*; Terada, Hiroaki; Nagai, Haruyasu; Takigawa, Masayuki*; et al.
Atmospheric Environment, 214, p.116830_1 - 116830_11, 2019/10
Times Cited Count:6 Percentile:21.73(Environmental Sciences)The utilization of numerical atmospheric dispersion prediction (NDP) models for accidental discharge of radioactive substances was recommended by a working group of the Meteorological Society of Japan. This paper is to validate the recommendation through NDP model intercomparison in the accidental release from the Fukushima Dai-ichi Nuclear Power Plant in 2011. Emission intensity is assumed to be constant during the whole forecast period for the worst-case scenario unless time sequence of emission is available. We expect to utilize forecasts of surface air contaminations for preventions of inhalations of radioactive substances, and column-integrated amounts for mitigation of radiation exposure associated with wet deposition. Although NDP forecasts have ensemble spread, they commonly figure out relative risk in space and time. They are of great benefit to disseminating effective warnings to public without failure. The multi-model ensemble technique may be effective to improve the reliability.
Sato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qulo, D.*; et al.
Journal of Geophysical Research; Atmospheres, 123(20), p.11748 - 11765, 2018/10
Times Cited Count:47 Percentile:84.74(Meteorology & Atmospheric Sciences)A model intercomparison of the atmospheric dispersion of Cs emitted following the Fukushima Daiichi Nuclear Power Plant accident was conducted by 12 models to understand the behavior of
Cs in the atmosphere. The same meteorological data, horizontal grid resolution, and an emission inventory were applied to all the models to focus on the model variability originating from the processes included in each model. The multi-model ensemble captured 40% of the observed
Cs events, and the figure-of-merit in space for the total deposition of
Cs exceeded 80. Our analyses indicated that the meteorological data were most critical for reproducing the
Cs events. The results also revealed that the differences among the models were originated from the deposition and diffusion processes when the meteorological field was simulated well. However, the models with strong diffusion tended to overestimate the
Cs concentrations.
Mikami, Satoshi; Sato, Shoji*; Hoshide, Yoshifumi*; Sakamoto, Ryuichi*; Okuda, Naotoshi*; Saito, Kimiaki
Hoken Butsuri, 50(3), p.182 - 188, 2015/09
Intercomparison of in situ spectrometry was organized at a site contaminated by the radioactive fallout that originated from the Fukushima Dai-ichi Nuclear Power Plant accident. This intercomparison was conducted by eight teams from four different institutions, which have contributed to the government-led project to construct distribution maps of radionuclides deposited on the ground soil. The resultant
Cs and
Cs inventories evaluated by the participants agreed within 6% of the coefficient of variation, after correction for inhomogeneous distribution of the air dose rate. The evaluated
K inventories agreed within 4% of the coefficient of variation. The authors estimated that these results were in good agreement for creating distribution maps of the radionuclide inventory in the ground soil.
Yamamoto, Hideaki; Yoshizawa, Michio; Murakami, Hiroyuki; Momose, Takumaro*; Tsujimura, Norio*; Kanai, Katsuta*; Cruz-Suarez, R.*
Radiation Protection Dosimetry, 125(1-4), p.88 - 92, 2007/07
Times Cited Count:0 Percentile:0.00(Environmental Sciences)The purpose of this paper is to discuss the results of the third intercomparison exercise of external radiation dosimetry organized under the Regional Cooperative Agreement (RCA) in the East Asia region of the International Atomic Energy Agency (IAEA). Twenty five laboratories from 16 member states participated in the exercise. Japan Atomic Energy Research Institute (JAERI) and Japan Nuclear Cycle Development Institute (JNC) arranged the standard irradiation of the participants' dosimeters. The results of the measurements of the irradiated dosimeters for the determination of external doses were satisfactory for all participants, demonstrating good performance in their external dosimetry.
Mehta, K.*; Kojima, Takuji; Sunaga, Hiromi
Radiation Physics and Chemistry, 68(6), p.959 - 962, 2003/12
Times Cited Count:3 Percentile:25.40(Chemistry, Physical)Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters:ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 -ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement of better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.
Takeda, Seiji; Kimura, Hideo
JAERI-Research 2002-014, 20 Pages, 2002/07
no abstracts in English
Manokhin, V. N.*; Odano, Naoteru; Hasegawa, Akira
JAERI-Data/Code 2001-019, 169 Pages, 2001/07
Results of comparison of (n,2n) and (n,3n) reaction cross sections for 155 nuclei (Ge - Tb) in JENDL-3.2 with available experimental data, various evaluated data, and those estimated from systematics are summarized to assess validity of cross sections for threshold reactions for fission product nuclei in JENDL-3.2. Plots for comparisons are compiled and issues in cross section data in JENDL-3.2 are also discussed.
H.H.Mai*; N.D.Duong*; Kojima, Takuji
IAEA-TECDOC-1070, p.345 - 351, 1999/03
no abstracts in English
L.G.Lanuza*; E.G.Cabalfin*; Kojima, Takuji; Tachibana, Hiroyuki
IAEA-TECDOC-1070, p.337 - 344, 1999/03
no abstracts in English
H.Camus*; R.Little*; D.Acton*; A.Agueero*; D.Chambers*; L.Chamney*; J.L.Daroussin*; J.Droppo*; C.Ferry*; E.Gnanapragasam*; et al.
Journal of Environmental Radioactivity, 42, p.289 - 304, 1999/00
Times Cited Count:19 Percentile:45.03(Environmental Sciences)no abstracts in English
Kojima, Takuji; Tachibana, Hiroyuki; ; ; P.H.G.Sharpe*
Radiation Physics and Chemistry, 54(6), p.619 - 626, 1999/00
Times Cited Count:10 Percentile:60.03(Chemistry, Physical)no abstracts in English
Takahashi, Tomoyuki; Takebe, Shinichi; Kimura, Hideo; Matsuzuru, Hideo; Yasuda, Hiroshi*; Uchida, Shigeo*; Saeki, Akiyoshi*; Mahara, Yasunori*; Sasaki, Noriyuki*; ; et al.
JAERI-Research 97-089, 25 Pages, 1997/12
no abstracts in English
Endo, Akira; Oishi, Tetsuya; Takahashi, Fumiaki; Murakami, Hiroyuki
JAERI-Conf 97-008, 184 Pages, 1997/06
no abstracts in English
Takada, Hiroshi; Yoshizawa, Nobuaki*;
JAERI-Research 96-040, 91 Pages, 1996/08
no abstracts in English
H.H.Mai*; Ng.D.Duong*; Kojima, Takuji
Applied Radiation and Isotopes, 47(2), p.259 - 261, 1996/00
Times Cited Count:2 Percentile:24.51(Chemistry, Inorganic & Nuclear)no abstracts in English
S.R.Nilekani*; G.R.Narayan*; B.Suseela*; R.M.Bhat*; B.L.Gupta*; Kojima, Takuji; Takizawa, Haruki; Sunaga, Hiromi; Tanaka, Ryuichi
Applied Radiation and Isotopes, 46(3), p.205 - 207, 1995/00
Times Cited Count:5 Percentile:57.30(Chemistry, Inorganic & Nuclear)no abstracts in English
D.Nichiporov*; V.Kostjuchenko*; J.M.Puhl*; D.L.Bensen*; M.F.Desrosiers*; C.E.Dick*; W.L.Mclaughlin*; Kojima, Takuji; B.M.Coursey*; S.Zink*
Applied Radiation and Isotopes, 46(12), p.1355 - 1362, 1995/00
Times Cited Count:31 Percentile:92.24(Chemistry, Inorganic & Nuclear)no abstracts in English
Kojima, Takuji; H.L.A.Ranjith*; Haruyama, Yasuyuki; Kashiwazaki, Shigeru*; Tanaka, Ryuichi
Applied Radiation and Isotopes, 44(1-2), p.41 - 45, 1993/00
Times Cited Count:12 Percentile:73.99(Chemistry, Inorganic & Nuclear)no abstracts in English
Saito, Kimiaki; Nagaoka, Toshi; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Moriuchi, Shigeru;
JAERI-M 90-188, 40 Pages, 1990/11
no abstracts in English