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Amano, Tsukasa; Shibata, Ryodai; Sato, Yoshiharu; Yamazaki, Katsuyuki; Shiromo, Hideo; Nakamura, Hironobu
Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 6 Pages, 2023/05
In Japan, about 10 years have passed since the law obligated nuclear operators to develop and maintain a nuclear security culture. During this period, the global nuclear situation has changed significantly, and it is becoming important to maintain a stance that emphasizes compliance with regulations and nuclear security culture. In JAEA, the policy of legal compliance and developing nuclear security culture is determined by the president of JAEA. For legal compliance and developing nuclear security culture, many activities are carried out based on that policy. Finally, these activities are evaluated and improved it every year. Case study is the one of activities that can obtain skills for legal compliance and developing nuclear security culture, such as sensitivity of nuclear security risks, correct understanding of the laws. The procedure for the case study was created with reference to a method called KY-Training which is often applied to safety training program in Japan. KY-Training is a training that participants (groups) can reach the conclusion how to respond to cases through four questions. Firstly, participants are given illustrations and descriptions which has potential of nuclear security risks. Then, participants make discussion according to four questions. Consequently, participants can effectively become aware of nuclear security risks. In the 2022 case study, we prepared 23 cases so that they can select choose freely according to role of participants such as in charge of nuclear security, guards, general employees. Finally, participants are asked to fill a questionnaire to evaluate effectiveness of case study. The result of questionnaires indicated that the case study was able to lead to improvement sensitivity of nuclear security risks and correct understanding of the laws. Overall, case study results suggested that JAEA's efforts were implying sufficiently to develop and maintain a nuclear security culture.
Amano, Tsukasa; Sato, Yoshiharu; Shibata, Ryodai; Yamazaki, Katsuyuki; Shiromo, Hideo; Nakamura, Hironobu
Dai-43-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2022/11
About ten years have passed since the introduction of nuclear security compliance and security culture development activities. While there have been changes in domestic and international situations, it is essential for nuclear security that the entire organization maintains an attitude that emphasizes compliance with laws and regulations and nuclear security. JAEA has been effectively implementing various activities with evaluation and improvement. Especially, e-learning which combines education and awareness, case studies, and internal audits are considered effective in maintaining nuclear security compliance and security culture development activities.
Lin, P.*; Xu, C.*; Kaplan, D. I.*; Chen, H.*; Yeager, C. M.*; Xing, W.*; Sun, L.*; Schwehr, K. A.*; Yamazaki, Hideo*; Kokubu, Yoko; et al.
Science of the Total Environment, 678, p.409 - 418, 2019/08
Times Cited Count：13 Percentile：49.32(Environmental Sciences)Nagasaki sediments containing bomb-derived Pu provided a unique opportunity to explore the long term geochemical behavior of Pu. Through a combination of selective extractions and molecular characterization via electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry, we determined that 55 
3% of the 
Pu was preferentially associated with more persistent organic matter compounds in Nagasaki sediments, particularly those natural organic matter (NOM) stabilized by Fe oxides. Other organic matter compounds served as a secondary sink of these Pu (31 2% on average), and less than 20% of the Pu was immobilized by inorganic mineral particles. While present long-term disposal and environmental remediation modeling assume that solubility limits and sorption to mineral surfaces control Pu subsurface mobility, our observations suggest that NOM undoubtedly plays an important role in sequestering Pu. Ignoring the role of NOM in controlling Pu fate and transport is not justified in most environmental systems.
Sasaki, Hirokazu*; Nishikubo, Hideo*; Nishida, Shinsuke*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Isomatsu, Takemi*; Minato, Ryuichiro*; Kinugawa, Kohei*; Imamura, Akihiro*; Otomo, Shinya*; et al.
Furukawa Denko Jiho, (138), p.2 - 10, 2019/02
no abstracts in English
(3) be made?Akahane, Keiichi*; Iimoto, Takeshi*; Ichiji, Takeshi*; Iwai, Satoshi*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; Kurosawa, Tadahiro*; Tatsuzaki, Hideo*; Tsujimura, Norio; et al.
Hoken Butsuri, 50(4), p.257 - 261, 2015/12
In a mixed field of photon and beta radiations, the same dose assigned to skin is normally assigned to the dose to the lens of the eye as a conservative estimate of H
(3). In exceptional cases that a very high beta dose might be imparted of the same order with the dose limit, however, the conservatively biased dose must be too limiting, and thereby an accurate estimate of beta (3) is desirable. This article presents a practical proposal of when and how the dosimetry of beta (3) should be made.
Akahane, Keiichi*; Iimoto, Takeshi*; Ichiji, Takeshi*; Iwai, Satoshi*; Oguchi, Hiroyuki*; Ono, Kazuko*; Kawaura, Chiyo*; Tatsuzaki, Hideo*; Tsujimura, Norio; Hamada, Nobuyuki*; et al.
Hoken Butsuri, 49(3), p.153 - 156, 2014/09
A brief review is given of the history and methodology of external dosimetry for the lens of the eye. Under the 1989 revision to domestic radiological protection regulations, the concept on the effective dose equivalent and the dose limit to the lens of the eye (150 mSv/y) both introduced in ICRP 1977 recommendations has changed nationwide the external monitoring methodology in non-uniform exposure situations to the trunk of a radiological worker. In such situations, often created by the presence of a protective apron, the worker is required to use at least two personal dosemeters, one worn on the trunk under the apron and the other, typically, at the collar over the apron. The latter dosemeter serves the dual purpose of providing the dose profile across the trunk for improved effective dose equivalent assessment and of estimating the dose to lens of the eye. The greater or appropriate value between (10) and (0.07), given by the dosemeter, is generally used as a surrogate of (3).
Katahira, Kenshi*; Moriwaki, Hiroshi*; Ishitake, Miho*; Kokubu, Yoko; Yamazaki, Hideo*; Yoshikawa, Shusaku*
Soil and Sediment Contamination, 22(8), p.1003 - 1012, 2013/07
Times Cited Count：1 Percentile：3.04(Environmental Sciences)The objective of this study was to reveal historical changes in environmental pollution, including the influence of the Nagasaki atomic bomb, based on heavy metal concentrations in sediment core samples. Lead isotope ratios were used to determine the sources of Pb. A sediment core was sampled from a reservoir about 3 km east of the hypocenter of the Nagasaki atomic bomb. It was reported in a previous study that this sediment core contained high activities of 
Pu and 
Cs at the 1945 layer as a result of the Nagasaki atomic bomb. Concentrations of heavy metals and the Pb isotope ratios in sediments were measured using ICP-MS. The results show a spiked peak in the Pb concentrations in the same layer as that of the Pu and Cs. It is thought that the spiked peak is due to the loading of Pb by the Nagasaki atomic bombing, and this is supported by further results showing that the Pb isotope ratios in this layer were different from those in other layers.
Yamazaki, Hideo*; Yoshikawa, Shusaku*; Kokubu, Yoko
Reametaru Binran, 3, p.661 - 663, 2010/12
no abstracts in English
Kokubu, Yoko; Yamazaki, Hideo*
Isotope News, (673), p.8 - 13, 2010/05
no abstracts in English
Cs released from Nagasaki atomic bomb in sediment of Nishiyama reservoir at NagasakiKokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*; Mitamura, Muneki*; et al.
Journal of Environmental Radioactivity, 99(1), p.211 - 217, 2008/01
Times Cited Count：19 Percentile：40.5(Environmental Sciences)In a sediment core of Nishiyama reservoir at Nagasaki, depth profiles of 
Pu/
Pu ratio, Pu and Cs concentrations were determined. Sediments containing plutonium and Cs, which were fallout deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout. This is the first entire depositional records of plutonium and Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
Journal of Radioanalytical and Nuclear Chemistry, 273(1), p.183 - 186, 2007/07
Times Cited Count：7 Percentile：47.34(Chemistry, Analytical)no abstracts in English
Cs found in the surface soils of Nagasaki, JapanKokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*
Journal of Geosciences, Osaka City University, 50, p.7 - 13, 2007/03
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
KEK Proceedings 2006-5, p.36 - 40, 2006/11
no abstracts in English
Isozaki, Kazunori; Saito, Takakazu; Sumino, Kozo; Yamazaki, Yuji*; Karube, Koji; Terano, Toshihiro; Sakaba, Hideo
JNC TN9410 2004-014, 172 Pages, 2004/06
JNC-TN9410-2004-014.pdf:48.0MB
This technical report describes MK-III function tests on the primary main cooling pump. MK-III function tests (SKS-1) before MK-III core configuration completed from October 17, 2001 to October 23, 2001. MK-III function tests (SKS-2) after MK-III core configuration completed from January 27, 2003 to February 13, 2003. The results of function tests were shown as follows; (1) The primary main pump was confirmed to do stable control on both CAS (cascade) mode and MAN (manual) mode in the flow control system. And also this was confirmed no-emanation trend both flow and revolution per minute against flow step response, too. (2) The main motor was shifted run-back operation in about 54 seconds after scram. Run-back operation of the main motor (A) was 167m3/h with 117 rpm. 185 m
/h with 118 rpm was the main motor (B). And they were controlled within the limit of run-back operational revolution 122 rpm 8 rpm. The flow was confirmed to maintain in 10 percent and over of the rated flow. (3) Succeeding operation to the pony motor was confirmed to do in about 39 seconds after the primary main pump trip. The pony motor (A) operation was 180m3/h with 124rpm. 190 m/h with 123 rpm was the pony motor (B). They were enough satisfied with the forgiven revolution per minute which was 93 rpm and over. And the flow was confirmed to maintain in 10 percent and over of the rated flow. (4) Free flow coast down characteristic of the primary main pump was confirmed that time constant was 10 seconds at both the trip and run-back operation time of the primary main pump. (5) Over flow column sodium level of the main pump duty operation was NL-1,550 mm Na by column (A), NL-1,468mm Na by column (B). They were smaller than NL-1,581 mm Na by the design value. Pressure loss value of the new IHX had more conservative value than the design value. (6) The primary main pump was confirmed which the rated flow could be restored no-scram by the instantaneous power loss within 0.6 second.
Kasagi, Jirota*; Yamazaki, Hirohito*; Galster, W.*; Saito, Akiko*; Harada, Hideo; Furutaka, Kazuyoshi; Shcherbakov, O.
JNC TY8400 2002-002, 64 Pages, 2002/05
JNC-TY8400-2002-002.pdf:1.81MB
no abstracts in English
pulse-shape discrimination with simple pile-up rejection at high -ray count rates*; Yamazaki, Hirohito*; *; Kasagi, Jirota*; Harada, Hideo
Nuclear Instruments and Methods in Physics Research A, 426(2-3), p.497 - 502, 1999/05
Times Cited Count：7 Percentile：49.91(Instruments & Instrumentation)None
OHarada, Hideo; Shigetome, Yoshialki; Ogaki, H.*; Noguchi, T.*; Yamazaki, Tetsuo*
Physical Review Letters, 80(1), p.33 - 36, 1998/01
Times Cited Count：24 Percentile：74.54(Physics, Multidisciplinary)None
Kasagi, Jirota*; Kinoshita, Tadashi*; Yorita, Tetsuhiko*; Yamazaki, Hirohito*; Harada, Hideo; Shigetome, Yoshialki
PNC TY8601 97-001, 12 Pages, 1997/03
no abstracts in English
Shigetome, Yoshiaki; Harada, Hideo; Noguchi, Tsutomu*; Yamazaki, Tetsuo*
JAERI-Conf 96-008, p.223 - 226, 1996/03
None
Kunugi, Tomoaki; Akiba, Masato; Ogawa, Masuro; Ise, Hideo*; Yamazaki, Seiichiro*
Fusion Technology, 21, p.1863 - 1867, 1992/05
no abstracts in English
