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Hayashida, Takeshi*; Uemura, Yohei*; Kimura, Kenta*; Matsuoka, Satoshi*; Hagihara, Masato; Hirose, Sakyo*; Morioka, Hitoshi*; Hasegawa, Tatsuo*; Kimura, Tsuyoshi*
Physical Review Materials (Internet), 5(12), p.124409_1 - 124409_10, 2021/12
Times Cited Count:17 Percentile:77.72(Materials Science, Multidisciplinary)Saito, Tatsuo; Sakai, Akihiro; Sato, Kazuhiko; Yagi, Naoto; Hata, Haruhi; Fumoto, Hiromichi*; Kawagoshi, Hiroshi; Hasegawa, Makoto
JAEA-Review 2014-021, 30 Pages, 2014/07
Japan Atomic Energy Agency surveyed the reference cases for the disposal of uranium bearing waste in low activity concentration as the contents of their own category 2 waste disposal facility for the Research and Development Activities. We reviewed the concepts mentioned in IAEA and ICRP documents, reference cases of uranium bearing waste disposal in selected countries (USA, Canada, UK, France and Sweden), and the disposal styles of long-lived radioactive waste were summarized, and the action items for application to the disposal system of our country was arranged. The disposal facilities in selected countries can be classified into 2 types with the length of performance assessment period for intruder scenario. They are long term assessment type and short term assessment type. It seems that the disposal system construction in category 2 waste disposal is the most realistic since there are many precedence examples of each country. Correspondence of 2 types of these disposal facilities is useful as a reference case.
Sato, Kazuhiko; Sakai, Akihiro; Hata, Haruhi; Fumoto, Hiromichi*; Kawagoshi, Hiroshi; Saito, Tatsuo; Hasegawa, Makoto
JAEA-Review 2014-006, 78 Pages, 2014/03
In this paper, we report the result of survey for basic principle of safety assessment for long-lived low-level (LL-LL) waste disposal and experience of the industrial waste disposal sites for uranium bearing waste in France, UK and Sweden, following the report of survey for U.S.A. and Canada published in December 2013.
Hasegawa, Makoto; Saito, Tatsuo; Zaitsu, Tomohisa; Sato, Kazuhiko; Sakai, Akihiro; Fumoto, Hiromichi*
JAEA-Review 2013-043, 42 Pages, 2013/12
Uranium bearing waste in Japan is not included in Category-2 radioactive waste disposal in NSCRG: F-RW-I.02 (published in August 2010, NSC Japan). Therefore, disposal of uranium bearing waste should be considered in institutionalization. In charge of the consideration, it is thought effective to refer to the proven tactics of the uranium waste disposal in overseas and the information on a safe regulatory system. Since the view of regulations and enterprises in this field are progressing day by day, renewal of the existing information of disposal of the uranium waste in each country is required. Furthermore, amendment of the U.S. federal rule aiming at safety disposal of depleted uranium is in progress. It is important to collect and arrange the latest information on the two above-mentioned points. Therefore, it visited the disposal responsible organization and regulatory agency of the disposal site of the uranium waste in the U.S. and Canada, and held institution investigations and interviews paying attention to the following four items: (1) "amendment of the U.S. 10CFR61", (2) "Safety evaluation of uranium bearing waste", (3) "Disposal site design", (4) "Stakeholder involvement".
Ishizuka, Akihiro; Nozaki, Tatsuo; Kokubun, Yuji; Okubo, Koichi; Torii, Tatsuo; Takata, Takushi*; Kume, Kyo*; Hasegawa, Takashi*; Sugita, Takeshi*
no journal, ,
The assessment methods of types and distributions of a radioactivity unexpectedly released to atmosphere from nuclear power plants have been studied with a help of examination of data measured by -ray detectors at several radiation monitoring equipments. The principle was verified with a -ray source in room, and an existing nuclear power station was simulated as an application example.
Takata, Takushi*; Ishizuka, Akihiro; Nozaki, Tatsuo; Kokubun, Yuji; Okubo, Koichi; Torii, Tatsuo; Kume, Kyo*; Otani, Nobuo*; Hasegawa, Takashi*
no journal, ,
The assessment methods of a radioactivity distribution unexpectedly released to atmosphere from nuclear power plants have been studied using a single channel analyzing technique. A combination of this single channel analyzing technique and a detector sensitive to a solid angle of an incident -ray was examined to assess the same purpose.
Torii, Tatsuo; Sanada, Yukihisa; Yamada, Tsutomu; Orita, Tadashi; Muraoka, Koji*; Sato, Masayuki*; Watanabe, Akira*; Kume, Kyo*; Hasegawa, Takashi*; Sugita, Takeshi*
no journal, ,
Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, an airplane, and the ground observation. On the measurement inside the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for -rays, and for /-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of 2 GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the -rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Then, we measured the variation of the energetic radiation from the top of the thundercloud using an airplane. At this time, we used two NaI detectors different in the size. We performed the radiation measurement by flying around the thunderclouds at 12 - 14 km in height by the observation in the summer. Moreover, in the winter season, we flew 5 - 6 km in height and measured the radiation around the thunderclouds. Furthermore, we carried out a ground observation of the energetic rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the JpGU meeting.