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Sato, Rina; Yoshimura, Kazuya; Sanada, Yukihisa; Mikami, Satoshi; Yamada, Tsutomu*; Nakasone, Takamasa*; Kanaizuka, Seiichi*; Sato, Tetsuro*; Mori, Tsubasa*; Takagi, Marie*
Environment International, 194, p.109148_1 - 109148_8, 2024/12
Times Cited Count：0 Percentile：0.00(Environmental Sciences)Assessment of individual external doses from ambient dose equivalents is used for predictive and retrospective assessments where personal dosimeters are not applicable. However, it tends to contain more errors than assessment by personal dosimetry due to various parameters. Therefore, in order to accurately assess the individual dose from ambient dose equivalents, a model that estimates effective doses considering life patterns and the shielding effects by buildings and vehicles, were developed in this study. The model parameters were examined using robust datasets of environmental radiation measured in the areas affected by the Fukushima Daiichi Nuclear Power Station accident in 2020 to 2021. The accuracy of the model was validated by comparison with 106 daily personal doses measured in Fukushima Prefecture in 2020. The measured personal dose was well reproduced by the model-estimated effective dose, showing that the model can be used to assess the individual exposure dose, similar to personal dosimetry. Furthermore, this model is an effective tool for radiation protection, as it can estimate the individual dose predictively and retrospectively by using environmental radiation data.
Dohi, Terumi; Omura, Yoshihito*; Yoshimura, Kazuya; Sasaki, Takayuki*; Fujiwara, Kenso; Kanaizuka, Seiichi*; Nakama, Shigeo; Iijima, Kazuki
PLOS ONE (Internet), 16(5), p.e0251828_1 - e0251828_16, 2021/05
Times Cited Count：8 Percentile：38.10(Multidisciplinary Sciences)Dohi, Terumi; Muto, Kotomi; Yoshimura, Kazuya; Kanaizuka, Seiichi*; Iijima, Kazuki
KEK Proceedings 2019-2, p.14 - 19, 2019/11
In order to investigate the effect of topography, meteorological condition, etc., on the spatial distribution of air dose rate on the main plume path, we evaluated walking survey data of air dose rates on Mt. Koutaishi and Mt. Juman, directed in northwest of and approximately 33 km and 11 km from the FDNPP. Measurements were performed on two orbital routs with different constant altitudes and general mountain trails in each mountain. The measurement data were compared with airborne monitoring results to investigate the relation between the dose rate distribution and elevation and orientation. At Mt. Koutaishi, the air dose rate was particularly high on the east side of the mountain, and the significant dependence of direction on the dose rate distribution was observed. Furthermore, high dose rate near the mountain foot indicates possibility of large deposition of 
Cs due to the plume passage from the FDNPP. At Mt. Juman, uniformly distribution of air dose rate was observed, and effect of wet deposition was considered. These results suggest the possibility of different deposition mechanisms in mountain range unit.
Dohi, Terumi; Tagomori, Hisaya; Omura, Yoshihito*; Fujiwara, Kenso; Kanaizuka, Seiichi*; Iijima, Kazuki
Environmental Radiochemical Analysis VI, p.58 - 70, 2019/09
In this study we established a separation method for radiocaesium-bearing microparticles (CsMPs) from lichens using electron microscopic analysis. Lichens were first digested within hydrogen peroxide and then an automatic particle analyser system based on FE-EPMA was used for detecting CsMPs within lots of mineral-like and metallic particles quickly. The elemental composition and radiocaesium activities of the separated CsMPs were measured, and the results show that the digestion treatment did not influence the CsMPs characteristics. An inhomogeneous elemental distribution was found in some CsMPs by two-dimensional elemental analysis using FE-EMPA. Our methods for separation of CsMPs and analysing their elemental composition are expected to be useful for grasping the chemical composition trends of CsMPs statistically.
Tagomori, Hisaya; Dohi, Terumi; Ishii, Yasuo; Kanaizuka, Seiichi*; Fujiwara, Kenso; Iijima, Kazuki
JAEA-Technology 2019-001, 37 Pages, 2019/03
JAEA-Technology-2019-001.pdf:26.85MB
An efficient methodology for separating the radiocaesium-bearing micro particles (CsMPs) released by the TEPCO's Fukushima Dai-ichi Nuclear Power Station accident is required to investigate their spatial distribution and physicochemical properties. In this report we developed an efficiency separation method for CsMP from litters since the radiocaesium in litter may affect the radiocaesium cycling in forest ecosystem. One CsMP separation from litter containing lots of soil particles was attained within three days using electron microscopic analysis with digestion treatment of organic matter. This methodology is expected as CsMPs efficient separation method for not only forest floor litter but also barks and leaves of living tree, and other organic materials in the forested environment.
Hidaka, Akihide; Nakano, Yoshihiro; Watanabe, Yoko; Arai, Nobuyoshi; Sawada, Makoto; Kanaizuka, Seiichi*; Katogi, Aki; Shimada, Mayuka*; Ishikawa, Tomomi*; Ebine, Masako*; et al.
JAEA-Review 2016-011, 208 Pages, 2016/07
JAEA-Review-2016-011-01.pdf:33.85MBJAEA-Review-2016-011-02.pdf:27.68MB
JAEA has been conducting the Instructor Training Program (ITP) since 1996 under the auspices of MEXT to contribute to human resource development in currently 11 Asian countries in the field of radiation utilization for seeking peaceful use of nuclear energy. ITP consists of Instructor Training Course (ITC), Follow-up Training Course (FTC) and Nuclear Technology Seminars. In the ITP, trainings or seminars relating to technology for nuclear utilization are held in Japan by inviting nuclear related people from Asian countries to Japan and after that, the past trainees are supported during FTC by dispatching Japanese specialists to Asian countries. News Letter is also prepared to provide the broad range of information obtained through the trainings for local people near NPPs in Japan. The present report describes the activities of FY2014 ITP and future challenges for improving ITP more effectively.
Watanabe, Yoko; Arai, Nobuyoshi; Sawada, Makoto; Kanaizuka, Seiichi; Shimada, Mayuka*; Ishikawa, Tomomi*; Nakamura, Kazuyuki
JAEA-Review 2015-026, 38 Pages, 2015/11
JAEA-Review-2015-026.pdf:10.55MB
JAEA has conducted Nuclear Technology Seminar for Asian countries which plan to introduce NPP, in order to increase the number of engineers and specialists. The Nuclear Technology Seminar on the Basic Radiation Knowledge for School Education Course was launched in 2012 due to increased recognition of the dissemination of the basic knowledge of radiation in public and education sectors as an important issue in the aftermath of the Fukushima Dai-ichi NPP Accident. In response to the requests of past participants, a new exercise "Joint experiment with high school students" was introduced from 2014 to provide an international learning experience for the course participants and the local Japanese students. A new learning material was also developed to help participants to study the basics of radiation in English. All the course activities including the details of preparatory process and course evaluation were described in this report.
Dohi, Terumi; Iijima, Kazuki; Yoshimura, Kazuya; Omura, Yoshihito*; Fujiwara, Kenso; Kanaizuka, Seiichi*
no journal, ,
no abstracts in English
Sakurai, Takeshi; Yabuuchi, Yukiko; Arai, Nobuyoshi; Sawada, Makoto; Yamashita, Kiyonobu; Sato, Nobuyuki; Torata, Shinichiro; Kanaizuka, Seiichi; Nakamura, Kazuyuki
no journal, ,
Outline of the Instructor Training Program, which is contracted with MEXT, for ten countries in Asia, and status of the Follow-up Training Course, which is one of the three major courses and conducted in Asian countries, will be reported.
Nakamura, Kazuyuki; Arai, Nobuyoshi; Kanaizuka, Seiichi; Sakurai, Takeshi; Sawai, Tomotsugu; Sawada, Makoto; Nakagawa, Norio; Murakami, Hiroyuki; Yabuuchi, Yukiko; Yamashita, Kiyonobu; et al.
no journal, ,
JAEA is performing the human resource development for eleven Asian countries as contract with MEXT. Problems and their response to this works will be reported.
Sawada, Makoto; Yabuuchi, Yukiko; Arai, Nobuyoshi; Kanaizuka, Seiichi; Yamashita, Kiyonobu; Nakagawa, Norio; Murakami, Hiroyuki; Nakamura, Kazuyuki
no journal, ,
Outline of International Nuclear Human Resource Development Program (Instructor Training Program: ITP), which is sponsored by MEXT, for Asian ten countries by JAEA will be reported. ITP consists of three major activities, i.e. Instructor Training Course, Follow-up Training Course and Nuclear Safety seminars. 16 years training activity from 1996 at JAEA and Asian countries has developed around 160 of instructors and more than 2,000 of trainees in Asian countries.
Muto, Kotomi; Dohi, Terumi; Yoshimura, Kazuya; Kanaizuka, Seiichi*; Iijima, Kazuki
no journal, ,
no abstracts in English
Oda, Yoshihiro; Dohi, Terumi; Kanaizuka, Seiichi*; Iijima, Kazuki
no journal, ,
We make a research to understand the detailed distribution of radioactive caesium deposition on mountain forests around Fukushima Dai-ichi Nuclear Power Plant. By the research data, we analysed the relations between dose rate and landform by using geographical information system.
Sato, Tetsuro*; Yoshimura, Kazuya; Sato, Rina; Kanaizuka, Seiichi*; Sanada, Yukihisa; Ando, Masaki; Saito, Kimiaki
no journal, ,
From FY2014, researches on estimation of exposure dose when residents return to areas where evacuation orders have been canceled by interviewing living behavior routes and measuring air dose rates covering the entire routes have been carried out. We will report the specifications and the accuracy of exposure dose simulator developed in this study.
Kinase, Sakae; Uno, Kiichiro*; Ojima, Emi*; Kanaizuka, Seiichi*; Shikaze, Yoshiaki; Ando, Masaki; Mikami, Satoshi; Saito, Kimiaki
no journal, ,
no abstracts in English
Tagomori, Hisaya; Ishii, Yasuo; Kanaizuka, Seiichi*; Dohi, Terumi; Iijima, Kazuki
no journal, ,
In order to evaluate the chemical form and distribution of radionuclide in soil and litter near the Fukushima Daiichi Nuclear Power Plant, method for isolating radioactive particles were carried out. Main procedures for isolating radioactive particles are as follows; After drying and size classification, samples are decomposed with hydrogen peroxide. And then, IP method is carried out to monitor the distribution of radionuclide. A portion showing high radiation is selected as microscopic analysis which composed of Field Emission-Electron Prove Micro-Analyzer (FE-EPMA) and Energy-Dispersive X-ray Spectroscopy (EDS). As results of above method, several particles with unique elemental compositions such as Ba was identified. Moreover, methods for isolating particles of 100 - 200 um using the Micro Manipulator were established. The isolation of fine particles (less than 50 um), were also applied by the meaning of digging a trench on the carbon tape using Focused Ion Beam (FIB).
Dohi, Terumi; Tagomori, Hisaya; Omura, Yoshihito*; Kanaizuka, Seiichi*; Fujiwara, Kenso; Iijima, Kazuki
no journal, ,
no abstracts in English
Yoshimura, Kazuya; Kanaizuka, Seiichi*
no journal, ,
no abstracts in English
