Hoshasen To Sangyo, (146), p.48 - 52, 2019/06
no abstracts in English
Tsuda, Shuichi; Tanigaki, Minoru*; Yoshida, Tadayoshi; Saito, Kimiaki
Hoshasen, 44(3), p.109 - 118, 2018/11
JAEA has started to perform dose rate monitoring using a car-borne survey system KURAMA to rapidly produce the dose rate mappings of the deposited radionuclides in the environment after the Fukushima Dai-ichi Nuclear Power Plant accident. KURAMA is a car-borne survey system developed by Kyoto University to perform dose rate monitoring in a wide area in detail with rapidity. By improving KURAMA with continuous dose rate monitoring, the 2nd generation of KURAMA (KURAMA-II) succeeded in downsizing, durability and automated transmission of data so that enable detailed dose rate mapping in wide area in shorter period of time. This paper reports the radiation characteristics and the simulation analysis of KURAMA-II on the special issue of Hoshasen, the journal of Ionization Radiation Division in the Japan society of applied physics.
Kai, Takeshi; Yokoya, Akinari*; Fujii, Kentaro*; Watanabe, Ritsuko*
Hoshasen Kagaku (Internet), (106), p.21 - 29, 2018/11
It is thought to that the biological effects such as cell death or mutation are induced by complex DNA damage which are formed by several damage sites within a few nm. As the prediction of complex DNA damage at an electron track end, we report our outcomes. These results indicate that DNA damage sites comprising multiple nucleobase lesions with a single strand breaks can be formed by multiple collisions of the electrons within 1 nm. This multiple damage site cannot be processed by base excision repair enzymes. Pre-hydrated electrons can also be produced resulting in an additional base lesion over a few nm from the multi-damage site. This clustered damage site may be finally converted into a double strand break. These DSBs include another base lesion(s) at their termini that escape from the base excision process and which may result in biological effect. Our simulation is useful to reveal phenomena involved in radiation physico-chemistry as well as the DNA damage prediction.
Tada, Junichiro*; Nakashima, Hiroshi; Hayano, Ryugo*; Kobayashi, Hitoshi*; Asano, Yoshihiro*
Wakariyasui Hoshasen Butsurigaku; Kaitei 3-Han, 305 Pages, 2018/03
This book is an introduction to radiation physics. Under the concept of "linking physics of high school and radiation physics" for readers with high school graduation degree, we are doing simple commentary on the basis of qualitative explanation as much as possible. This book begins with "What is Radiation Physics", and consists of 12 chapters, including introductory special relativity, introductory quantum theory, structures of atoms and nuclei, radiations, radioactivity, interactions between radiation and matter, accelerators, radiation dose and so on.
Hoshasen To Sangyo, (143), p.51 - 54, 2017/12
The author reports experience note of John Rogers laboratory in Northwestern University from January in 2017.
Nippon Hoshasen Anzen Kanri Gakkai-Shi, 16(2), P. 41, 2017/11
I summarized the outline of the oral presentation session where the author served as chairman.
Kitamura, Akane; Kobayashi, Tomohiro*
Hoshasen Kagaku (Internet), (104), p.29 - 34, 2017/10
no abstracts in English
Hoshasen To Sangyo, (142), p.34 - 37, 2017/06
no abstracts in English
Hoshasen, 43(2), p.49 - 54, 2017/05
no abstracts in English
Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuda, Norihiro; Iwase, Hiroshi*; Niita, Koji*
Hoshasen, 43(2), p.55 - 58, 2017/05
Particle and Heavy Ion Transport code System, PHITS, has been developed under the collaboration of several institutes in Japan and Europe. It can deal with the transport of nearly all particles up to 1 TeV (per nucleon for ion) using various nuclear reaction models and data libraries. More than 2,500 registered researchers and technicians have used this system for various applications such as accelerator design, radiation shielding and protection, medical physics, and space- and geo-sciences. This paper summarizes the physics models and functions recently implemented in PHITS, between versions 2.52 and 2.88.
Hata, Kuniki; Lin, M.*; Yokoya, Akinari*; Fujii, Kentaro*; Yamashita, Shinichi*; Muroya, Yusa*; Katsumura, Yosuke*
Hoshasen Kagaku (Internet), (103), p.29 - 34, 2017/04
Reactivity of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), which is known to show high antioxidative properties, with oxidative species, such as hydroxyl radical (OH) and azide radical (N), was investigated by a pulse radiolysis experiment, and generation behavior of edaravone radicals produced through these reactions were observed. It was shown that OH-adducts are produced by the reaction with OH in contrast to the other oxidative radicals, which react with edaravone by an electron transfer reaction. Chemical repair properties of edaravone against DNA lesions produced by reactions of DNA with oxidative species were also investigated by a pulse radiolysis experiment with deoxyguanosine monophosphate (dGMP) and a -radiolysis experiment with plasmid DNA solutions. It was observed that edaravone reduced dGMP radicals just after produced in a dilute aqueous solution and inhibited some base lesions on plasmid DNA more effectively than single strand breaks. These results show that edaravone may protect living system from oxidative stress, such as radiation, by not only scavenging oxidative species but also reducing precursors of DNA leisons.
Hoshasen Kagaku (Internet), (103), P. 65, 2017/04
no abstracts in English
Tomioka Hoshasen Joho Matome Saito (Internet), 2 Pages, 2017/01
Some radiation measurement instruments are lent out to the residents in Tomioka-machi, Fukushima. In this paper, it is explained that the kinds of those instruments, their purposes, the attention points on their uses and the interpretation of the measurement results by those instruments.
Genshiryoku, hoshasen Bukaiho (Internet), (19), P. 15, 2016/12
The Tritiated Water Task Force under METI's Committee on Countermeasures for Contaminated Water Treatment for Fukushima Daiichi Nuclear Power Plant (1F) reported that the option of post-dilution offshore release could dispose the tritiated water at a smallest cost in the shortest amount of time. The amount of tritium in the contaminated water at 1F was compared with ones released from nuclear power plants and reprocessing plants as some help for grasping its level of magnitude.
Sato, Tatsuhiko; Hamada, Nobuyuki*
Hoshasen Seibutsu Kenkyu, 51(4), p.397 - 401, 2016/12
A workshop entitled "Radiation Research Based on Computer Simulation" was held at the 59th annual meeting of the Japanese Radiation Research Society. Approximately 50 participants attended the workshop, and six speakers gave a talk about their computational radiation biology studies. The title of the presentations are "Research on DNA damage and track structure simulation", "Study of cellular response based on stochastic model for simulating irradiated and non-irradiated cells", "Effectiveness of mathematical model for low-dose radiation effect", "Research on particle therapy based on cell surviving fraction model", "Development of model for natural induction of cataract", and "Mathematical model for carcinogenesis considering the differences of temporal and spatial doses". In the workshop, possible future collaborations were intensively discussed. This report briefly summarizes the outline of the workshop.
Hoshasen To Sangyo, (141), p.7 - 11, 2016/12
Desulfurization is an indispensable process on hydrogen formation from fossil fuel. Adsorptive desulfurization, alternative to conventional hydrogenation desulfurization, requires development of stable activated carbon adsorbents with high performance. I study dopant dependence on thiophene adsorption for carbon alloys prepared by heteroatom doping using low-energy ion beam. I doped nitrogen and phosphorus as dopants of group 15 elements in graphite surfaces, and clarified that phosphorus is superior in thiophene adsorption to nitrogen, and that the effect of phosphorus is higher with room temperature doping than with high temperature doping by about 10 times. X-ray absorption spectroscopy indicated that local structures around phosphorus sites were different between them. I attribute the high adsorption property to formation of curved phosphorus sites prepared by room temperature doping. Above results suggest that the property of carbon alloy can be controlled by low-energy ion beam.
Kurita, Yoshiyuki; Saegusa, Jun; Maeda, Satoshi
Nippon Hoshasen Anzen Kanri Gakkai-Shi, 15(2), p.180 - 185, 2016/11
In 2012, JAEA has established a laboratory in Fukushima-city to implement radioactivity analysis of environmental samples. Key nuclides measured in this laboratory are Cs and Cs (radiocesium). For the purpose, situation of radiocesium inflow into the laboratory building and its effects were investigated based on high-resolution gamma-spectrometry with germanium detectors. As a result, the surface density of radiocesium in the laboratory was found to be far below the minimum detectable activities of survey instruments routinely used for radiation control purposes.
Tokuyasu, Kayoko; Furuta, Sadaaki*; Kokubu, Yoko; Umeda, Koji
Nippon Hoshasen Anzen Kanri Gakkai-Shi, 15(1), p.80 - 87, 2016/07
An optically stimulated luminescence reader (Riso TL/OSL DA-20) was installed in Toki Research Institute of Isotope Geology and Geochronology (Toki-shi, Gifu Prefecture), Japan Atomic Energy Agency (JAEA) for dating the geological sample. An accumulated dose of the sample is obtained using the reader. Sealed beta source of strontium-90 is required to be mounted on the reader because repeated artificial irradiation is necessary for the accumulated dose estimation. However, there are not many introduction examples for the reader domestically, and the information as to radiation control of the reader is limited. We therefore report here the process of source loading on the reader and radiation control associated with the use of the source.
Kai, Takeshi; Yokoya, Akinari; Fujii, Kentaro; Watanabe, Ritsuko
Hoshasen Kagaku (Internet), (101), p.3 - 11, 2016/04
Behavior analysis of low energy electrons in liquid water provides the fundamentals for successive radiation chemistry, and it makes analysis of DNA damage implication involved in the electrons possible. We have progressed theoretical studies for radiation physicochemical process of liquid water to clear the role of low-energy secondary electrons damage to DNA. The process has included many unknown factors for the DNA damage so far. Based on the results, we implied a newly formation process of unrepair DNA damage produced by the secondary electrons assumed that it was ejected from DNA by impact of a high energy electron. We report our outcomes separately in three manuscripts entitled "Recent progress of radiation physicochemical process (first, second, third parts)" to journal of radiation chemistry. In this first part, we outline recent status of studies for the DNA damage and the radiation physicochemical process, we also show calculation method of electron impact cross sections involved strongly in electron deceleration in liquid water in the topics of our outcomes. From the calculated results, we also report our prediction, which are different from previous one, for electron thermalization.
Izumi, Yudai; Yamamoto, Satoshi*; Fujii, Kentaro; Yokoya, Akinari
Hoshasen Seibutsu Kenkyu, 51(1), p.91 - 106, 2016/03
no abstracts in English