Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sato, Tatsuhiko; Funamoto, Sachiyo*; Paulbeck, C.*; Griffin, K.*; Lee, C.*; Cullings, H.*; Egbert, S.*; Endo, Akira; Hertel, N.*; Bolch, W.*
no journal, ,
Owing to recent advances in computational dosimetry tools, it is desirable to update the dosimetry system for the atomic-bomb survivors, DS02. The DS02 system is based on adjoint Monte Carlo particle transport simulations coupled with stylized computational human phantoms. We therefore developed the J45 series of computational voxel phantoms representative of 1945 Japanese adults, children, and pregnant females, as a part of international collaboration project between RERF and several institutes in Japan and USA. Using those phantoms, we calculated organ doses in adults for 12 representative exposure scenarios having realistic particle energy and angular fluence, using the latest Monte Carlo particle transport codes, PHITS and MCNP. Those data were compared with survivor organ doses given by the DS02 system. It was found that overall impacts of introducing the new computational method in the dosimetry system are not so significant, less than 10% in most cases, except for organs whose calculation method or definition was changed such as colon and bone marrow. The current status of this international collaboration project will be presented at the meeting.
Sato, Tatsuhiko; Kataoka, Ryuho*; Shiota, Daiko*; Kubo, Yuki*; Ishii, Mamoru*; Yasuda, Hiroshi*; Miyake, Shoko*; Miyoshi, Yoshizumi*
no journal, ,
We are developing a physics-based warning system for aviation exposure to solar energetic particles, WASAVIES, under the framework of the PSTEP project in Japan. It can nowcast and forecast the radiation dose rates all over the world up to 24 h after the large solar flare onset. The performance of WASAVIES is examined by analyzing the three major GLE events of the 21st century. The accuracy of the calculated dose rates is well validated by the reproducibility of the count rates of several neutron monitors and GOES proton fluxes. A web-interface of WASAVIES was also developed and released via the public server of NICT.
Manabe, Kentaro; Matsumoto, Masaki*
no journal, ,
When an insoluble cesium-bearing particle which has high specific activity is inhaled into the human body, the activity will move stochastically in the state of a sphere without dissolving in the blood or tissue fluid. We have developed a stochastic biokinetic method to evaluate the stochastic behavior of the particle in the body and estimated the probability distribution of exposure doses from a typical cesium-bearing particle whose diameter is 2 
m. In this study, we analyzed particle diameter dependence of dose distribution due to inhalation of the particle with considering that the activity in a particle and the deposition probability to the regions of the respiratory tract change with the diameter. As a result, the maximal values of 99%ile values and arithmetic means were observed at 3.0 m and 3.5 m, respectively.
Takahashi, Fumiaki; Manabe, Kentaro; Sato, Kaoru
no journal, ,
The International Commission on Radiological Protection (ICRP) has published dose coefficients for internal exposure dose evaluation in accordance with dose assessment methods in the 2007 Recommendations based on newly obtained findings. In the future, if the policy of ICRP 2007 Recommendation is incorporated into national radiation regulations, standards for internal exposure protection are to be revised based on the new coefficients. Therefore, JAEA has developed an internal dose assessment code to verify whether the dose coefficient published by the ICRP has been accurately derived from fundamental dosimetry models and data or not, through a project commissioned by the Nuclear Regulatory Agency. The code also implements functions for radiation dose management and emergency dose assessment at each site based on the 2007 Recommendations. In this presentation, we will report the outline of the beta version of the code developed and examples of its application.
Kim, M.; Malins, A.; Machida, Masahiko; Yoshimura, Kazuya; Yoshida, Hiroko*; Saito, Kimiaki
no journal, ,
no abstracts in English
Saito, Tatsuo
no journal, ,
Task Group discussed the issues regarding the radiation protection of waste containing natural radionuclides from the perspective of radiation protection. The exposure of the disposal of uranium generated from uranium treating facilities is in planned exposure situation, but may become a source of existing exposure when the institutional control of the repository is over. Uranium disposal is insignificant as the source of exposure to future generations when a disposal plan of no more than 1 Bq/g or 1 mSv/year is established before the institutional control is finished. If only uranium that can be disposed of within the framework of planned exposure can be disposed of, there may be legacy uranium. For future generations that inherit the existing exposure of uranium, it is necessary to consider what the present generation should do and how far it should fulfill its exposure assessment or reduction.
Katengeza, E.*; Sanada, Yukihisa; Ochi, Kotaro; Iimoto, Takeshi*
no journal, ,
When radiocesium (RCs) deposits in water bodies, it tends to concentrate at the waterbed due to its strong adsorption to sediments. Monitoring wide areas of so-contaminated waterbed is challenging by traditional sediment sampling. In-situ techniques that can directly measure radioactivity in the waterbed are important solutions. However, their accuracy is generally lower than that of sediment sampling. This study presents the status of research on the application of in-situ radioactivity measurement technology in the waterbed focusing on RCs monitoring in Fukushima as spearheaded by the Japan Atomic Energy Agency (JAEA).
Morifuji, Masayuki; Hamataka, Kazuhito; Kokubun, Yuji; Yoshida, Tadayoshi; Shiba, Kozo
no journal, ,
no abstracts in English
Tsujimura, Norio
no journal, ,
no abstracts in English
Yoshida, Hiroko*; Kuroda, Yujiro*; Kono, Takahiko; Naito, Wataru*; Sakoda, Akihiro
no journal, ,
no abstracts in English
Sakoda, Akihiro; Tanaka, Hiroshi; Kanzaki, Norie
no journal, ,
no abstracts in English
Momose, Takumaro; Hayakawa, Tsuyoshi; Takada, Chie; Nakano, Masanao; Yoshida, Tadayoshi
no journal, ,
no abstracts in English
Inoue, Yuki; Yamada, Junya; Maeda, Eita; Hatakeyama, Takumi; Miyauchi, Hideaki; Hashimoto, Makoto
no journal, ,
no abstracts in English