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Tsuda, Shuichi; Saito, Kimiaki
no journal, ,
Air dose rate monitoring has been performed since the Fukushima Dai-ichi Nuclear Power Plant accident happened. In the measurement, NaI(Tl) and CsI(Tl) detectors are used, which are usually used in nuclear power plants and calibrated in a uniform irradiation condition in a radiation calibration field. In general, however, the detector responses are dependent on incident direction and in reality, the incident direction of the photons is not uniform in the environment. In this study, the spectrum - dose conversion operator (G(E) function) for h*(10) in a semi-infinite radiation field were obtained using the PHITS code for common scintillation detectors. The results indicate that the detectors obtain the doses within 20% accuracy under the real environment. The results for general scintillation detectors with various crystal configuration and size will be also reported.
Hirouchi, Jun; Takahara, Shogo; Iijima, Masashi; Watanabe, Masatoshi; Munakata, Masahiro
no journal, ,
no abstracts in English
Kimura, Daisuke; Hikinuma, Yuichi; Tanabe, Masanori; Makino, Tatsuya; Maegawa, Yoshiharu; Hayata, Kenichi*; Shiotani, Junya*; Nohara, Naofumi; Hoshi, Katsuya; Tsujimura, Norio; et al.
no journal, ,
no abstracts in English
Tsujimura, Norio; Takahashi, Fumiaki; Takada, Chie
no journal, ,
no abstracts in English
Hoshi, Katsuya; Yoshida, Tadayoshi; Tsujimura, Norio; Okada, Kazuhiko
no journal, ,
no abstracts in English
Watanabe, Yuki; Nakamura, Keisuke; Akasu, Kohei; Okuyama, Shun; Namiki, Atsushi
no journal, ,
no abstracts in English
Yoshida, Tadayoshi; Tsujimura, Norio; Hoshi, Katsuya
no journal, ,
no abstracts in English
Nakamura, Keisuke; Sugimoto, Tetsuya*; Maehata, Keisuke*; Iyomoto, Naoko*; Ishibashi, Kenji*; Morishita, Yuki; Takasaki, Koji; Mitsuda, Kazuhisa*
no journal, ,
no abstracts in English
Suga, Takumi; Yamazaki, Takumi; Takada, Chie; Takimoto, Misaki; Okada, Kazuhiko
no journal, ,
no abstracts in English
Mori, Airi; Ishizaki, Azusa; Imura, Mitsuo*; Munakata, Masahiro
no journal, ,
no abstracts in English
Hokama, Tomonori; Nishimura, Tomohiro; Nakano, Masanao
no journal, ,
It is difficult to judge abnormality using variation of air dose rate after the Fukushima Daiichi Nuclear Power Plant accident. The purpose it setting band of air dose rate after the accident using trend of air dose rate. We divide tendency of dose rate into three Category and estimate band of air dose rate after the accident.
Sakoda, Akihiro; Ishimori, Yuu
no journal, ,
Many studies of radioactive concentrations in plants and soil-to-plant transfer factors have been reported after the Fukushima accident. In the present study, the concentrations of stable elements as well as radionuclides in plants sampled in Fukushima were determined. As a result, there were correlations of measured concentrations in the plants to some degree between alkaline-earth metals and Sr-90, although no obvious correlations between alkali metals and Cs-137. The present results were generally consistent with many previous studies, although further discussion would be necessary.
Ishimori, Yuu; Sakoda, Akihiro
no journal, ,
JAEA has performed the soil cover test at the mill tailing dam, and has routinely obtained data on its effect. In the present study, relative concentrations of radon in soil were observed using CR-39 detectors for a year. It was demonstrated that the soil cover suppressed enough the exhalation of radon originating from the tailings. The calibration of the detection system and the modeling of radon behavior in soil are now addressed to present the influence of tailings in the near future.
Masuyama, Koichi; Sato, Koichi; Yoshino, Koji; Tajima, Takahiro*; Seki, Kazunari; Kasugai, Yoshimi; Miyamoto, Yukihiro
no journal, ,
The mercury target vessel used in the Materials and Life Science Experimental Facility (MLF) in the Japan Accelerator Research Complex (J-PARC) needs to be replaced periodically. The replacement work, which is conducted in the hot cell, associates with release of radioactive materials produced via spallation reactions between protons and mercury. Therefore we monitored radioactivity of dust and air samples in the hot cell. By the monitoring, we newly found peculiar phenomena on the behavior of radioactive products, which is important for radiation control. In this work, we will show the monitoring data and the new observation.
Kinase, Sakae; Murakami, Yuko; Takahashi, Tomoyuki*; Suzuki, Tadakazu*; Sugita, Takeshi*; Ando, Masaki; Mikami, Satoshi; Yamamoto, Hideaki; Saito, Kimiaki
no journal, ,
no abstracts in English
Aoki, Katsunori; Ogura, Hideki; Kubota, Mitsuru; Tsurudome, Koji; Ikeda, Koki; Nagasaki, Yasushi; Ogata, Nobuhisa; Furuta, Sadaaki*
no journal, ,
no abstracts in English
Takeishi, Minoru; Shibamichi, Masaru; Murakami, Mitsuhiro; Saegusa, Jun
no journal, ,
no abstracts in English
Shimada, Kazumasa; Kai, Michiaki*
no journal, ,
This paper describes lung cancer mortality risks due to radiation exposure considering the history of smoking in Japanese people. In this study, we calculated the DALY of lung cancer mortality for Japanese males considering the joint effects of radiation and smoking using the generalized multiplicative excess relative risk interaction model (GM model). First, we estimated the lung cancer baseline risk for non-smokers to divide the risk of smoking for mixed population groups that include smokers and non-smokers. Second, we developed a radiation risk model from single to chronic exposure to be able to evaluate the risk of cancer in existing and control exposure situations. Forth, the maximum relative risks of lung cancer mortality for smokers and non-smokers induced by a radiation exposure of 20 mGy/y for Japanese smokers between the age of 20 and 60 years were calculated using the GM model to be 22.2 for men and 15.7 for women, respectively. Therefore, our calculations show that only considering radiation risks strongly underestimate the real risk of lung cancer when the smoking history is not taken into account. Our study indicates that estimations of the health risk due to radiation exposure should consider not only age and gender but also the history of smoking for deriving an occupational exposure limit.
Tomita, Jumpei; Abe, Takuya; Sakaguchi, Aya*; Miyata, Yoshiki*; Nagao, Seiya*; Yamamoto, Masayoshi*
no journal, ,
no abstracts in English
Takeishi, Minoru
no journal, ,
no abstracts in English