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Yoshimura, Kazuya; Sanada, Yukihisa; Sato, Rina; Nakayama, Mariko*; Tsubokura, Masaharu*
Journal of Radiation Research (Internet), 64(2), p.203 - 209, 2023/03
Times Cited Count：0 Percentile：0.01(Biology)After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, individual exposure doses to residents have been assessed by many municipalities, governments and research institutes. Various methods including measurements with personal dosimeters and simulations have been used for this evaluation depending on purposes, but the information of assessments and methods has not been systematically organized. A comprehensive review of the knowledge and experiences of individual exposure doses assessments accumulated so far and understanding the characteristics of the assessment methods will be very useful for radiation protection and risk communication, following to governmental policy planning. We reviewed the efforts made by the Japanese government and research institutes to assess radiation doses to residents after the FDNPS accident in Part1. On the other hand, each method of assessing individual exposure doses includes uncertainties and points to be considered for the appropriate assessment. These knowledge and experiences are important for the assessment implementation and applying the assessment results to the governmental policy planning, and are summarized in Part2 of this article.
Shimada, Kazumasa; Iijima, Masashi*; Watanabe, Masatoshi*; Takahara, Shogo
Proceedings of Asian Symposium on Risk Assessment and Management 2021 (ASRAM 2021) (Internet), 17 Pages, 2021/10
The radiation doses received by the off-site responders in the Fukushima Daiichi Nuclear Power Station accident were assessed. Atmospheric dispersion simulation was conducted with the source term of the previous research to calculate the atmospheric concentration and ground surface deposition in the municipalities where off-site responders actives. The external exposure dose from cloudshine and groundshine, the internal exposure dose due to inhalation of radioactive plume and resuspended radio nuclei, and the temporal and spatial distribution within each municipality were assessed. As a result of comparing the assessed values of the external exposure dose with the measured values of the personal dosimeter, the measured values were within the assessed range. As a result of our assessment with internal dose exposure, if the exposures occurred without protective measures, the potential daily effective dose in the period between 12 and 31 March 2011 were several tens mSv per day or more in the relatively high dose area. Therefore, to keep the doses received by the responders below the reference level of 20 mSv recommended by the ICRP, it is necessary to ensure that the protective measures for internal exposures such as masks are taken, and to manage the time spent for their activity at least daily.
Sugaya, Toshikatsu; Abe, Daichi*; Okada, Shota; Nakata, Hisakazu; Sakai, Akihiro
JAEA-Technology 2021-004, 79 Pages, 2021/05
JAEA-Technology-2021-004.pdf:2.86MBJAEA-Technology-2021-004(errata).pdf:0.38MB
JAEA has aims to carry out near surface disposal of low-level radioactive waste generated from research, medical, and industrial facilities. Therefore, radioactivity concentration corresponding to dose criteria of near surface disposal for 220 nuclides in the waste were calculated for the purpose of discussion for radioactivity limits between trench and concrete vault disposal, and key nuclides related to them. We calculated the radioactivity concentrations with consideration of not only the exposure pathways used at calculation of the radioactivity concentration limits of waste packages for near surface disposal by Nuclear Safety Commission but also ones used at the concentration limits for intermediate depth disposal. We also assumed the capacities of the disposal facilities as 44,000 m
for pit disposal and 150,000 m for trench disposal. The radioactivity concentrations calculated in this report is used as the reference values because the disposal site has not been decided yet. Addition to this, the radioactivity concentrations will be revised according to circumstances of development of disposal facilities and so on. In the future, we will decide the radioactivity and radioactive concentration of a waste package described in the license application documents based on the dose assessment taken into consideration the disposal site conditions.
Tomita, Jumpei
Bunseki, 2019(3), p.112 - 113, 2019/03
no abstracts in English
Sato, Kaoru; Takahashi, Fumiaki; Endo, Akira; Ono, Koji*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Ban, Nobuhiko*; Kai, Michiaki*
RIST News, (58), p.25 - 32, 2015/01
The Japan Atomic Energy Agency (JAEA) are now developing WAZA-ARI for improvement of management of exposure doses due to CT examination under the joint research with the Oita University of Nursing and Health Sciences. The trial version of WAZA-ARI has been released on 21 December 2012. In trial version, users can perform dose assessment by using organ dose database based on the average adult Japanese male (JM-103) and female (JF-103) voxel phantoms and a 4 years old female voxel phantom (UFF4). The homepage of WAZA-ARI has been accessed over 1000 times per month and 28421 times by the end of September 2014. We are developing WAZA-ARI version 2 as the extension version of dose calculation functions of WAZA-ARI. WAZA-ARI version 2 will be released by the end of March 2015. In WAZA-ARI version 2. Users can upload dose calculation results to WAZA-ARI version 2 server, and utilize improvement of the dose management of patients and the optimization of CT scan conditions.
Sato, Kaoru; Noguchi, Hiroshi; Emoto, Yutaka*; Koga, Sukehiko*; Saito, Kimiaki
Radiation Protection Dosimetry, 123(3), p.337 - 344, 2007/02
Times Cited Count：39 Percentile：91.43(Environmental Sciences)A Japanese adult male voxel (volume pixel) phantom (hereinafter referred to as the JM phantom) was constructed on the basis of CT images of a healthy Japanese adult male volunteer. Body characteristics of the JM phantom were compared with those of a voxelized MIRD5 type phantom and a Japanese adult male voxel phantom which was previously developed. The voxel size of the JM phantom is 0.98
0.981 mm. The shapes of organs of the JM phantom, even for small or complicated organs, such as thyroid and stomach, are more realistically reproduced as compared with the previous Japanese voxel phantom (voxel size: 0.980.9810 mm). Photon self-absorbed fractions for brain, kidneys, spleen, pancreas, thyroid and urinary bladder wall of JM were evaluated and were compared with those of the other phantoms. In consequence, it was suggested that the mass, shape and thickness of organs are important factors for the determination of self-absorbed fractions.
Yamaguchi, Yasuhiro; Hirayama, Hideo*
Journal of Nuclear Science and Technology, 41(Suppl.4), p.498 - 501, 2004/03
JAERI-Universities Joint Research Project has been carried out to study the radiation safety in high-energy proton accelerator facilities since 2000. Ten groups from 2 research institutes and 5 universities joined in the project to tackle 3 major subjects below, using a quasi-monoenergetic neutron field at TIARA facility of JAERI. The groups had annual meetings to discuss the plan and progress of the studies and exchange their views for effective cooperation. (1)Studies on basic physical data necessary for neutron dosimetry. (2)Development of neutron monitors and dosimeters for several tens MeV region. (3)Studies on formation of radioactive aerosols and gases for internal dosimetry.
Kimura, Hideo; Takeda, Seiji; Takahashi, Tomoyuki*
JAERI-Data/Code 99-033, 54 Pages, 1999/06
JAERI-Data-Code-99-033.pdf:2.13MB
no abstracts in English
Amano, Hikaru
Purazuma, Kaku Yugo Gakkai-Shi, 73(12), p.1360 - 1361, 1997/12
no abstracts in English
Yamaguchi, Yasuhiro
Nihon Genshiryoku Gakkai-Shi, 36(7), p.624 - 630, 1994/00
Times Cited Count：2 Percentile：28.09(Nuclear Science & Technology)no abstracts in English
Sato, Kaoru; Takahashi, Fumiaki; Endo, Akira; Ono, Koji*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Ban, Nobuhiko*; Kai, Michiaki*
no journal, ,
The Japan Atomic Energy Agency are now developing WAZA-ARI for improvement of management of exposure doses due to CT examination under the joint research with the Oita University of Nursing and Health Sciences. The trial version of WAZA-ARI has been released to the public via the home page of the National Institute of Radiological Sciences for test operation. In trial version, users can perform dose assessment against average adult Japanese by using organ dose database based on the JM-103 (male) and JF-103 (female) phantoms with average body sizes of adult Japanese. To expand functions of WAZA-ARI to enables users to perform against adult patients with other body sizes, we developed the adult Japanese phantoms with small, large and extra-large body sizes by modifying JM-103 and JF-103. By dose analysis based on these phantoms, it was concluded that organ doses per current are strongly dependent on body sizes.
Koba, Yusuke*; Matsumoto, Shinnosuke*; Nakada, Yoshihiro*; Kasahara, Tetsuji*; Akahane, Keiichi*; Okuda, Yasuo*; Sato, Kaoru; Takahashi, Fumiaki; Yoshitake, Takayasu*; Hasegawa, Takayuki*; et al.
no journal, ,
Many of the CT devices are in Japan. It is guessed that exposure doses of Japanese derived from CT scans are higher than others. Thus, it is needed to properly manage scan conditions and exposure doses of individual patients. JAEA developed WAZA-ARI under the collaboration research project with the National Institute of Radiological Sciences (NIRS) and the Oita University of Nursing and Health Sciences. Practical use of new version WAZA-ARI named WAZA-ARIv2 began on January 30, 2015 at the web server in NIRS. In WAZA-ARIv2, users can calculate patients doses by using only standard condition (120 kV) of X-tube voltage. In recent years, CT scans at low tube voltage against pediatric patients with high radiosensitivity are increasing. In this study, spectrum of X-ray derived from CT scan at low tube voltage was examined, and was defined in "usrsors.f" file of PHITS. We reported the characteristics of X-ray and organ doses derived from CT scan at low tube voltage (80 kV).
Ono, Koji*; Koba, Yusuke*; Matsumoto, Shinnosuke*; Nakada, Yoshihiro*; Okuda, Yasuo*; Akahane, Keiichi*; Sato, Kaoru; Takahashi, Fumiaki; Yoshitake, Takayasu*; Hasegawa, Takayuki*; et al.
no journal, ,
In medical treatment, CT scan is useful diagnostic method. On the other hand, exposure doses derived from CT scans are dependent on body sizes of patients. Therefore, consideration of body sizes is essential for accurate dose assessment of individual patients. JAEA developed the CT dose calculator, WAZA-ARIv2 under the collaboration research project with the National Institute of Radiological Sciences and the Oita University of Nursing and Health Sciences. WAZA-ARIv2 enable users to accurately calculate exposure doses of patients with sexes, ages (0y, 1y, 5y, 10y, 15y and adult) and fatness (small, large and extra-large body sizes). In the future, we will be plans to add the dose calculation functions corresponding to the scan conditions at low tube voltage and multi-detector row (more 80) CT devices to WAZA-ARIv2. We reported the system and future plans of WAZA-ARIv2 corresponding to dose calculation of patients with various body sizes.
Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Effective doses based on ICRP 2007 Recommendations are evaluated using sex averaged equivalent doses. On the other hand, it is required that the situations of exposure are considered as possible in estimating doses for radiation accidents and medical interventions. Then, there are sex specific organs and differences between males and females in masses and positions in bodies of organs (physical characteristics). It is useful to reveal an impact of these differences in physical characteristics on dose estimation. In this study, a comparison was made with organ doses between male and female using photon and electron SAFs based on Japanese adult male and female phantoms (male: JM-103, female: JF-103), which have average physiques and organ masses of adult Japanese, and the recent nuclear decay data and biokinetic models of ICRP. As a result, it is revealed that several tens of percent of discrepancies in organ doses between male and female was caused by sex differences in physical characteristics.
Tomita, Jumpei; Abe, Takuya; Sakaguchi, Aya*; Miyata, Yoshiki*; Nagao, Seiya*; Yamamoto, Masayoshi*
no journal, ,
no abstracts in English
Terada, Hiroaki; Nagai, Haruyasu; Katata, Genki; Tsuzuki, Katsunori; Akari, Shusaku*
no journal, ,
During the Fukushima Daiichi Nuclear Power Station accident which is necessary for accurate estimation of doses to the public, atmospheric dispersion simulations were conducted by using an atmospheric dispersion model underdevelopment Japan Atomic Energy Agency. The simulations were done by a latest meteorological model WRF and a particle dispersion model GEARN which has detailed deposition scheme considering different chemical forms. Surface deposition distribution in east Japan measured by airborne survey was largely reproduced by the simulation using the four-dimensional variational assimilation method (4D-Var) with meteorological observation data near the site and the latest estimated source term. Hereafter, we aim to estimate more accurate source term based on the comparison with the measurements such as air concentrations of 
Cs, etc.
Mori, Airi; Ishizaki, Azusa; Tanabe, Tsutomu; Wada, Takao; Kato, Mitsugu; Munakata, Masahiro
no journal, ,
no abstracts in English
Saito, Kimiaki
no journal, ,
no abstracts in English
Takimoto, Misaki; Yamazaki, Takumi; Takada, Chie; Okada, Kazuhiko; Endo, Akira; Yoshizawa, Michio; Momose, Takumaro
no journal, ,
no abstracts in English
Yoshida, Hiroko*; Shinohara, Naohide*; Manabe, Kentaro; Higaki, Shogo*
no journal, ,
no abstracts in English
