Radiation and spintronics

Ieda, Junichi

Hoshasen To Sangyo, (146), p.48 - 52, 2019/06

no abstracts in English

Estimating internal dose coefficients of short-lived radionuclides in accordance with ICRP 2007 Recommendations

Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

Journal of Nuclear Science and Technology, 56(5), p.385 - 393, 2019/05

https://doi.org/10.1080/00223131.2019.1585988

At high energy accelerator facilities, various radionuclides are produced by nuclear reactions of high energy particles with structure and/or ambient air of the facilities. Consequently, the radionuclides are potential sources of internal exposure for works of the facilities. However, the International Commission on Radiological Protection (ICRP) do not provide dose coefficients, which are committed effective doses per intake, for the short-lived radionuclides whose half-lives are shorter than 10 minutes in accordance with the ICRP 2007 Recommendations. Then, we estimated the dose coefficients for inhalation and ingestion of these short-lived radionuclides in accordance with the ICRP 2007 Recommendations. In addition, we compared the dose coefficients with those in accordance with the ICRP 1990 Recommendations. As a result, a decreasing tendency was shown in the dose coefficients for inhalation cases; an increasing tendency was observed in those for ingestion cases. It was found that these changes in dose coefficients were mainly caused by the revision of the dose calculation procedures, alimentary tract models. The result of this study will be useful for planning of radiation protection at the high energy facilities.

Units of radiation (radioactivity)

Takahashi, Fumiaki

Genshiryoku No Ima To Ashita, p.109 - 111, 2019/03

The Atomic Energy Society of Japan has planned to publish a document for public, entitled "Current and tomorrow of atomic energy, -Experiences from the accident at the Tokyo Electronic Power Company Fukushima Dai-ichi NPPs-". The documents give us basics and usages of radiations, in addition to nuclear power plants and the accident at TEPCO Fukushima Dai-ichi NPPs. This manuscript explains physical quantities (e.g., absorbed dose), protection quantities and operational quantities that are used for radiation measurement and protection. The unit of radioactivity is also explained, because radioactivity is measured for work places in a radiation facility for internal exposure protection. In addition, radiation dose constants that relate radiation dose to the activity are also introduced, as useful radiation units for radiation protection.

Reaction between spin-correlated triplet positronium and OH radical in water

Hirade, Tetsuya

JPS Conference Proceedings (Internet), 25, p.011022_1 - 011022_3, 2019/03

https://doi.org/10.7566/JPSCP.25.011022

OH radicals which are very reactive are formed by radiation decomposition in water. The behavior of OH radicals is important in corrosion of materials and reactions in living bodies. Recently, the reaction occurring between positronium (Ps) formed by OH radicals formed at the end of the positron track when positron is incident and positronium (Ps) formed by reaction of excess electrons formed with OH radical formation with the thermo-positron, it is reported that quantum beat occurs due to spin correlation. This quantum beat seems to have a period depending on the hyperfine coupling constant of OH radical. It is thought that the period and intensity of the quantum beat depends on the temperature, and it seems that it reflects the state around the OH radical. From the temperature dependence of the quantum beat detected by the reaction of this spin-correlated OH radical and triplet positronium we will explain what the liquid structure might be.

Testing of criticality accident alarm system detectors to pulsed radiation at TRACY

Tsujimura, Norio; Yoshida, Tadayoshi; Sanada, Yukihisa

JPS Conference Proceedings (Internet), 24, p.011013_1 - 011013_6, 2019/01

https://doi.org/10.7566/JPSCP.24.011013

Development of an air dose rate evaluation system (3D-ADRES) for complex real environments in Fukushima Prefecture; Using remote sensing data and evaluating the influence of different features (topography, soil, buildings, trees, etc.)

Kim, M.; Malins, A.; Sakuma, Kazuyuki; Kitamura, Akihiro; Machida, Masahiko; Hasegawa, Yukihiro*; Yanagi, Hideaki*

RIST News, (64), p.3 - 16, 2018/09

To improve the accuracy of simulations for air dose rates over fallout contaminated areas, the distribution of the radionuclides within the environment should be modelled realistically, e.g. considering differences in radioactivity levels between agricultural land, urban surfaces, and forest compartments. Moreover simulations should model the shielding of rays by buildings, trees and land topography. Here we outline a system for generating three dimensional models of urban and rural areas in Fukushima Prefecture. The Cs and Cs radioactivity distribution can be set flexibly across the different components of the model. The models incorporate realistic representations of local buildings, based on nine common Japanese designs, individual conifer and broadleaf trees, and the topography of the land surface. Models are generated from Digital Elevation Model (DEM) and Digital Surface Model (DSM) datasets, and refined by users assisted with ortho-photographs of target sites. Completed models are exported from the system in a format suitable for the Particle and Heavy Ion Transport code System (PHITS) for the calculation of air dose rates and other radiological quantities. The system is demonstrated by modelling a suburban area 4 km from the Fukushima Daiichi Nuclear Power Plant that has yet to be decontaminated. Air dose rates calculated in PHITS were correlated with measurements taken across the site in a car-borne survey.

The ICRU proposal for new operational quantities for external radiation

Otto, T.*; Hertel, N. E.*; Bartlett, D. T.*; Behrens, R.*; Bordy, J.-M.*; Dietze, G.*; Endo, Akira; Gualdrini, G.*; Pelliccioni, M.*

Radiation Protection Dosimetry, 180(1-4), p.10 - 16, 2018/08

https://doi.org/10.1093/rpd/ncx243

Report Committee 26 of the ICRU proposes a set of operational quantities for radiation protection for external radiation, directly based on effective dose and for an extended range of particles and energies. It is accompanied by new quantities for estimating deterministic effects to the eye lens and the local skin. The operational quantities are designed to overcome the conceptual and technical shortcomings of those presently in use. This paper describes the proposed operational quantities, and highlights the improvements with respect to the present legal monitoring quantities.

English translation of material used at "Meeting to Answer Questions on Radiation"

Kono, Yuko; Ayame, Junko; Yoshida, Tomoo*; Ikuta, Yuko; Kawase, Keiichi; Yamashita, Kiyonobu

JAEA-Review 2018-007, 36 Pages, 2018/06

JAEA-Review-2018-007.pdf:6.72MB

English translation of the material used at "Meeting to Answer Questions on Radiation" was made. "Meeting to Answer Questions on Radiation" was planned, just after the TEPCO Fukushima Daiichi Nuclear Power Plant Accident, by Japan Atomic Energy Agency (JAEA) with the purpose of providing comprehensive knowledge of radiation to the public. A total of 220 meetings was carried out from July, 2011 to February, 2013 mainly in Fukushima prefecture. Since the material used in the meetings contains many charts and is easy to understand, it has drawn attention of the International Atomic Energy Agency (IAEA) who has in recent years actively supported outreach activities to disseminate knowledge on nuclear and radiation. At one of the IAEA meetings in May, 2017, Asian Network for Education in Nuclear Technology (ANENT), it was requested to make it for the usage of all. Providing IAEA and the member states with the English translation of the material will be a meaningful contribution sharing the outreach activity experiences in Japan.

Investigation of hydrogen gas generation by radiolysis for cement-solidified products of used adsorbents for water decontamination

Sato, Junya; Kikuchi, Hiroshi*; Kato, Jun; Sakakibara, Tetsuro; Matsushima, Ryotatsu; Sato, Fuminori; Kojima, Junji; Nakazawa, Osamu

QST-M-8; QST Takasaki Annual Report 2016, P. 62, 2018/03

http://repo.qst.go.jp/?action=repository_uri&item_id=34490

no abstracts in English

Knowledge discovery of suppressive effect of disease and increased anti-oxidative function by low-dose radiation using self-organizing map

Kanzaki, Norie; Kataoka, Takahiro*; Kobashi, Yusuke*; Yunoki, Yuto*; Ishida, Tsuyoshi*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*

Radioisotopes, 67(2), p.43 - 57, 2018/02

https://doi.org/10.3769/radioisotopes.67.43

We previously reported that low-dose radiation induces the anti-oxidative function in many organ systems of mice. This results in the suppression of several kinds of oxidative stress-induced damage. This study was conducted with the objective of revealing the health effects of low-dose radiation obtained from our previous reports and searching for a new treatment based on low-dose radiation, such as radon therapy. We extracted the characteristics of the effects of low dose radiation suppressing diseases and enhancing the anti-oxidative function using fuzzy answer by self-organizing map (SOM) based on mutual knowledge. The relationship between the suppressive effect and increased antioxidative function was shown in our result, and the concentration dependence of the effect against pain was shown on the output map. Although the effect against other organs depending on concentration was unpredictable, our results indicate that low-dose radiation may also be suitable for treatment of liver disease and brain disease.