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Mikami, Satoshi; Tanaka, Hiroyuki*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Ochi, Kotaro; Uno, Kiichiro*; Matsuda, Norihiro; Saito, Kimiaki
Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(4), p.159 - 178, 2021/12
In order to know the background radiation level where the area affected by the Fukushima Daiichi Nuclear Power Plant accident in 2011, terrestrial gamma rays had been measured by using portable germanium detectors repeatedly from 2013 through 2019, at 370 locations within 80 km radius area centered on the Fukushima Daiichi Nuclear Power Plant. Radioactive concentrations of Uranium 238, Thorium 232, Potassium 40 and kerma rates in air due to terrestrial gamma rays were obtained at those locations based on the method of ICRU report 53. Averaged concentrations of U, Th and K were 18.8, 22.7, 428 Bq/kg, respectively, and kerma rate in air over the area was found to be 0.0402 Gy/h. The obtained kerma rates in air were compared to those reported in literatures. It was confirmed that the data were correlated with each other, and were agreed within the range of their uncertainty. This is because the kerma rate in air due to terrestrial gamma rays is depend on geology. The similar trend to previous findings was observed that the kerma rate in air at locations geologically classified as Mesozoic era, Granite and Rhyolite were statistically significantly higher than the others.
Noguchi, Hiroki; Kamiji, Yu; Tanaka, Nobuyuki; Takegami, Hiroaki; Iwatsuki, Jin; Kasahara, Seiji; Myagmarjav, O.; Imai, Yoshiyuki; Kubo, Shinji
International Journal of Hydrogen Energy, 46(43), p.22328 - 22343, 2021/06
Times Cited Count:12 Percentile:58.36(Chemistry, Physical)An iodine-sulfur process offers the potential for mass producing hydrogen with high-efficiency, and it uses high-temperature heat sources, including HTGR, solar heat, and waste heat of industries. R&D tasks are essential to confirm the integrity of the components that are made of industrial materials and the stability of hydrogen production in harsh working conditions. A test facility for producing hydrogen was constructed from corrosion-resistant components made of industrial materials. For stable hydrogen production, technical issues for instrumental improvements (i.e., stable pumping of the HIx solution, improving the quality control of glass-lined steel, prevention of I precipitation using a water removal technique in a Bunsen reactor) were solved. The entire process was successfully operated for 150 h at the rate of 30 L/h. The integrity of components and the operational stability of the hydrogen production facility in harsh working conditions were demonstrated.
Hosoda, Masahiro*; Nugraha, E. D.*; Akata, Naofumi*; Yamada, Ryohei; Tamakuma, Yuki*; Sasaki, Michiya*; Kelleher, K.*; Yoshinaga, Shinji*; Suzuki, Takahito*; Rattanapongs, C. P.*; et al.
Science of the Total Environment, 750, p.142346_1 - 142346_11, 2021/01
Times Cited Count:23 Percentile:85.26(Environmental Sciences)The biological effects of low dose-rate radiation exposures on humans remains unknown. In fact, the Japanese nation still struggles with this issue after the Fukushima Dai-ichi Nuclear Power Plant accident. Recently, we have found a unique area in Indonesia where naturally high radiation levels are present, resulting in chronic low dose-rate radiation exposures. We aimed to estimate the comprehensive dose due to internal and external exposures at the particularly high natural radiation area, and to discuss the enhancement mechanism of radon. A car-borne survey was conducted to estimate the external doses from terrestrial radiation. Indoor radon measurements were made in 47 dwellings over three to five months, covering the two typical seasons, to estimate the internal doses. Atmospheric radon gases were simultaneously collected at several heights to evaluate the vertical distribution. The absorbed dose rates in air in the study area vary widely between 50 nGy h and 1109 nGy h. Indoor radon concentrations ranged from 124 Bq m to 1015 Bq m. That is, the indoor radon concentrations measured exceed the reference levels of 100 Bq m recommended by the World Health Organization. Furthermore, the outdoor radon concentrations measured were comparable to the high indoor radon concentrations. The annual effective dose due to external and internal exposures in the study area was estimated to be 27 mSv using the median values. It was found that many residents are receiving radiation exposure from natural radionuclides over the dose limit for occupational exposure to radiation workers. This enhanced outdoor radon concentration might be as a result of the stable atmospheric conditions generated at an exceptionally low altitude. Our findings suggest that this area provides a unique opportunity to conduct an epidemiological study related to health effects due to chronic low dose-rate radiation exposure.
Sasaki, Ichiro; Hanaoka, Hirofumi*; Yamada, Keiichi*; Watanabe, Shigeki; Sugo, Yumi; Ohshima, Yasuhiro; Suzuki, Hiroyuki; Ishioka, Noriko
Peptide Science 2014, p.257 - 260, 2015/03
Fujii, Yasuhiko
Genshiryoku eye, 51(9), p.18 - 19, 2005/09
no abstracts in English
Fujii, Yasuhiko
Hoshasen To Sangyo, (107), p.2 - 3, 2005/09
no abstracts in English
Morii, Yukio; Imase, Hajime*
Hoshasen To Sangyo, (107), p.52 - 55, 2005/09
no abstracts in English
Amano, Hikaru; Ikeda, Hiroshi*; Sasaki, Toshihisa*; Matsuoka, Shungo*; Kurosawa, Naohiro*; Takahashi, Tomoyuki*; Uchida, Shigeo*
KEK Proceedings 2003-11, p.239 - 244, 2003/11
A Code MOGRA (Migration Of GRound Additions) is a migration prediction code for toxic ground additions including radioactive materials in a terrestrial environment, which consists of computational codes that are applicable to various evaluation target systems, and can be used on personal computers. The computational code has the dynamic compartment analysis block at its core, the graphical user interface (GUI) for model formation, computation parameter settings, and results displays. The code MOGRA has varieties of databases, which is called MOGRA-DB. Another additional code MOGRA-MAP can take in graphic map and calculate the square measure about the target land.
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; Torii, Yoshiya; Shibata, Yasushi*; Nose, Tadao*
Radiation Research, 160(1), p.70 - 76, 2003/07
Times Cited Count:16 Percentile:43.79(Biology)The survival curves and the RBE for the dose components generated in boron neutron capture therapy (BNCT) were determined separately in neutron beams at JRR-4. The surviving fractions of V79 cells with or without 10B were obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal (TNB-2) neutron beam. The cell killing effect of the neutron beam in the presence or absence of 10B was highly dependent on the neutron beam used and depended on the epithermal and fast-neutron content of the beam. The RBEs of the boron capture reaction were 4.07, 2.98 and 1.42, and the RBEs of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50, 2.34 and 2.17 for ENB, TNB-1 and TNB-2, respectively. The approach to the experimental determination of RBEs allows the RBE-weighted dose calculation for each dose component of the neutron beams and contributes to an accurate inter-beam comparison of the neutron beams at the different facilities employed in ongoing and planned BNCT clinical trials.
Nakai, Kei*; Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Zhang, T.*; Akutsu, Hiroyoshi*; Matsuda, M.*; Matsushita, Akira*; Yasuda, Susumu*; Takano, Shingo*; et al.
Research and Development in Neutron Capture Therapy, p.1135 - 1138, 2002/09
7 patients have been undergoing Intraoperative boron neutron capture therapy (IOBNCT) for malignant glioma at Japan Atomic Energy Institute (JAERI). Post-BNCT MRI studies revealed one local recurrence and two distant recurrences. Distant recurrence is uncommon in the conventional radiation therapy. Symptomatic late radiation necrosis occurred in one case.
Minehara, Eisuke
Nuclear Instruments and Methods in Physics Research A, 483(1-2), p.8 - 13, 2002/05
Times Cited Count:21 Percentile:77.32(Instruments & Instrumentation)In order to realize a tunable, highly-efficient, high average power, high peak power and ultra-short pulse free-electron laser(FEL) as a supertool [1]of the 21st for all , the JAERI FEL group and I have developed an industrial FEL driven by a compact, stand-alone and zero-boil-off super-conducting rf linac[2] with an energy-recovery geometry as a conceptual design. Our discussions on the supertool will cover market-requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil-off cryostat concept and operational experience over these 8 years, our discovery of the new, highly-efficient, high-power, and ultra-short pulse lasing mode[3], and the energy-recovery geometry.
Center for Neutron Science; Advanced Science Research Center
JAERI-Review 2002-002, 40 Pages, 2002/03
no abstracts in English
Minehara, Eisuke; Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Kikuzawa, Nobuhiro; Sugimoto, Masayoshi; Yamauchi, Toshihiko; Hayakawa, Takehito; Shizuma, Toshiyuki
Proceedings of 13th Symposium on Accelerator Science and Technology, p.150 - 154, 2001/10
We need a powerful and efficient free-electron laser(FEL) for industrial uses, for examples, pharmacy, medical, defense, shipbuilding, semiconductor industry, chemical industries, environmental sciences, space-debris, power beaming and so on. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, the JAERI FEL group and I have successfully demonstrated the efficient and powerful FEL driven by a compact, stand-alone and zero-boil-off super-conducting rf linac with an energy-recovery geometry. Our discussions on the FEL will cover market-requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil-off cryostat concept and operational experience over these 8 years, our discovery of the new, highly-efficient, high-power, and ultra-short pulse lasing mode, and the energy-recovery geometry.
Inaba, Yoshitomo; Fumizawa, Motoo*; Tonogochi, Makoto*; Takenaka, Yutaka*
Applied Energy, 67(4), p.395 - 406, 2000/12
Times Cited Count:10 Percentile:50.04(Energy & Fuels)no abstracts in English
Minehara, Eisuke
Isotope News, (559), p.8 - 10, 2000/12
no abstracts in English
Shimizu, Kenichi
Regional Training Course on National Safeguards Systems (CD-ROM), p.5 - 0, 2000/04
no abstracts in English
Matsumoto, Shiro*; Uchida, Shigeo*; Yamazawa, Hiromi; Amano, Hikaru
JAERI-Conf 99-001, 269 Pages, 1999/03
no abstracts in English
Inaba, Yoshitomo; Fumizawa, Motoo; Hishida, Makoto*; *; Takenaka, Yutaka*; Tonogochi, Makoto*
JAERI-Tech 96-057, 132 Pages, 1997/01
no abstracts in English
JAERI-Conf 94-003, 315 Pages, 1994/07
The 19th Linear Accelerator Meeting in Japan will be held at Tokai Research Establishment, Japan Atomic Energy Research Institute from July 20th through 22nd. One hundred papers will be presented, and over 300 participants gathered to hear, to perform and to discuss on their topical problems in the fields of linear accelerator theologies and their applications, The proceeding is prepared for all participants in the meeting, and it consists of the newly revised papers presented in the meeting which were administrated by Department of Reactor Engineering, Tokai Research Establishment, Japan Atomic Energy Research Institute.
Togawa, Orihiko
Hoken Butsuri, 29, p.55 - 64, 1994/00
no abstracts in English