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Endo, Akira
Annals of the ICRP, 52(4), p.5 - 7, 2024/12
In its Publication 155, International Commission on Radiological Protection (ICRP) has developed data on the Specific Absorbed Fraction (SAF) for reference males and females at ages of newborn, 1 year, 5 years, 10 years, and 15 years. The SAF represents the fraction of energy emitted within a source region which is absorbed in a target region per mass of the target region and is essential for calculating absorbed doses in organs or tissues for internal exposure. By combining the data of Publication 155 with the SAF data for reference adult males and females already published as Publication 133, an SAF dataset for the calculation of age-dependent dose coefficients for members of the public for environmental intakes of radionuclides has been completed. This, together with revised biokinetic models and nuclear decay data, means that the key building blocks for calculating new dose coefficients are in place. The outcome will soon be available in a series of ICRP Publications of Dose Coefficients for Intakes of Radionuclides by Members of the Public.
Miwa, Kazuji; Iimoto, Takeshi*
Journal of Radiation Protection and Research, 48(2), p.68 - 76, 2023/06
In the process of discussion on possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, strategy on the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. We proposed five interpretations of radiation protection to contribute the promotion of discussion on possibility of using a part of low-level-radionuclide-contaminated soil and debris in post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in post-accident rehabilitation when the sources are handled in a planned activity."
Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Takahashi, Yoshio*; Hirata, Takafumi*
Geostandards and Geoanalytical Research, 45(1), p.189 - 205, 2021/03
Times Cited Count:6 Percentile:28.89(Geochemistry & Geophysics)Uncertainty for elemental and isotopic analyses of calcite by LA-ICP-MS is largely controlled by the homogeneity of the reference materials (RMs) used for normalization and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb, and rare earth elements into calcite through heat- and pressure-induced crystallization from amorphous calcium carbonate that was precipitated from element-doped reagent solution. X-ray absorption spectra showed that U was present as U(VI) in the synthesized calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison to synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The
Pb/
Pb ratio in the calcite showed
1% variations, while the
U/
Pb ratio showed 3-24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC-1, with analytical uncertainty as low as
3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions, and is a promising alternative to natural calcite RMs for U-Pb geochronology.
Miwa, Kazuji; Shimada, Taro; Takeda, Seiji
Progress in Nuclear Science and Technology (Internet), 6, p.166 - 170, 2019/01
In this study, in order to validate the restricted use of recycling material at the reference radiocesium concentration (determined in series report (1)), we evaluated worker annual doses, air dose rate at the site boundary and impact of migrated radiocesium into groundwater. Firstly, we evaluated the additional annual dose for workers, on the assumption that typical workers coming in contact with the source after construction (Road: 1.2 mSv/y, Building: 1.3 mSv/y). Secondly, we evaluated the air dose rates by distance from road and building including recycling material, and investigated the distance for not exceeding 1 mSv/y (including additional dose rate by recycling and background dose rate of 0.6 mSv/y) at the site boundary (Road: 25 m, Building: 1 m). Thirdly, we evaluated the Cs migration in groundwater, and investigated the distance required for satisfying the operation target value (
Cs: 1 Bq/L,
Cs: 1 Bq/L) at the boundary (coastal line) (Road: 10 m, Building: 10 m).
Sugiyama, Daisuke*; Kimura, Hideo; Tachikawa, Hirokazu*; Iimoto, Takeshi*; Kawata, Yosuke*; Ogino, Haruyuki*; Okoshi, Minoru*
Journal of Radiological Protection, 38(1), p.456 - 462, 2018/03
Times Cited Count:0 Percentile:0.00(Environmental Sciences)Experience after the accident at the Fukushima Daiichi Nuclear Power Station has shown that there is a need to establish radiation protection criteria for radioactive waste management consistent with the criteria adopted for the remediation of existing exposure situations. A stepwise approach to setting such criteria is proposed. Initially, a reference level for annual effective dose from waste management activities in the range 1-10 mSv should be set, with the reference level being less than the reference level for ambient dose. Subsequently, the reference level for annual effective dose from waste management activities should be reduced in one or more steps to achieve a final target value of 1 mSv. The dose criteria at each stage should be determined with relevant stakeholder involvement. Illustrative case studies show how this stepwise approach might be applied in practice.
Tanimura, Yoshihiko; Saegusa, Jun; Yoshizawa, Michio; Yoshida, Makoto
Nuclear Instruments and Methods in Physics Research A, 547(2-3), p.592 - 600, 2005/08
Times Cited Count:11 Percentile:60.64(Instruments & Instrumentation)The moderator structure of a neutron spectrometer was optimized with a Monte Carlo code of MCNP-4B. The spectrometer consists of a cylindrical moderator and a position-sensitive thermal neutron detector. It can obtain an energy spectrum from thermal neutron distribution along the cylindrical axis of the moderator. The structure of the moderator was improved by putting a low hydrogen density material in the front of a high hydrogen density one and inserting a neutron absorber which eliminated thermal neutrons diffusing in the moderator. These improvements make energy resolution of the spectrometer better especially for the low energy neutrons from a few tens to 100 keV. The designed spectrometer can be applied to the measurement of energy spectrum over a neutron energy range from a few keV to 20 MeV.
Mizukoshi, Seiji; Oshima, Soichiro; Shimada, Taro
JAERI-Tech 2005-011, 122 Pages, 2005/03
The radiological and physical characteristic on decommissioning, such as component and structure weights and radioactivity of the 1.1 MWe class reference nuclear power plants summarized in the NUREG reports of the US NRC were classified,arranged and compared with the domestic commercial nuclear power plants and JPDR from a view point of dismantling plan and waste management for decommissioning. As the results, it was found that the radioactive component and structure weights was about 28,000ton、and non-radioactive structure weights was about 124,000ton less than the domestic commercial BWR. And it was found that this differences has mainly influenced dismantling costs for decommissioning. Farther, it was found that the concrete element composition rates of B, Ni, Nb and so were differerence of one or more figures btween the reference nuclear power plants and the domestic commercial PWR or JPDR.Also,it was found that the this difference became about two or three times by radioactivity concentration and has mainly influenced transport and disposal costs for decommissioning.
-ray analysis using 
-standardizationMatsue, Hideaki; Yonezawa, Chushiro
Bunseki Kagaku, 53(7), p.749 - 751, 2004/07
Times Cited Count:0 Percentile:0.00(Chemistry, Analytical)Multi-element determination in reference materials of soils (JASC401, JASC411) and sediments (NMIJ CRM 7302-a, NMIJ CRM 7303-a), which were prepared at the Japan Society for Analytical Chemistry and the National Institute of Advanced Industrial Science and Technology of the National Metrology Institute of Japan, respectively, has been carried out by neutron-induced prompt
-ray analysis (PGA) using standard addition and 
-standardization methods. Firstly, absolute Ti concentrations in the samples were determined accurately by the standard addition method. Secondly, relative multi-element concentrations were determined by the 
-standardization method. Finally, absolute multi-element concentrations were obtained by normalizing the relative multi-element concentrations with the absolute Ti concentration in the samples. The 15 elements such as H, B, Na, Si, S, Cl, K, Ca, Ti Cr, Mn, Fe, Cd, Sm and Gd were determined by the 
-PGA. Analytical results of these reference materials agreed with the certified or reference values within about 10%.
Shimizu, Shigeru; Zhang, Q.; Kajimoto, Yoichi; Kawasaki, Tomokatsu; Fujii, Katsutoshi
JAERI-Tech 2003-095, 52 Pages, 2004/01
The International Standards ISO4037-1 of the International Organization for Standardization widely applied in the world to construct X-ray reference fields for performance tests of radiation measuring instruments. The application of the current JAERI's X-ray reference field constructed in accordance with the Japanese Standards should be limited for domestic purposes becase of the characterization technique different from the International Standards. Therefore,for application to international performance tests, X-ray reference fields in the narrow,wide and high air-kerma series based on the International Standards were established using the medium-hard X-ray generator of the Facility of Radiation Standards(FRS), JAERI. This report presents quality characterization, estimation of X-ray spectra of each dose units of the new FRS's fields,and comparison of the qualities and the X-ray spectra to those of the ISO's. The FRS's qualities show good agreement with ISO's: the reference fields should serve for performance tests for international radiation protection purposes.
Nagaya, Yasunobu
Progress in Nuclear Energy, 39(2), p.145 - 153, 2001/08
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)no abstracts in English
Kojima, Takuji; Sunaga, Hiromi; Tachibana, Hiroyuki; Takizawa, Haruki; Tanaka, Ryuichi
IAEA-TECDOC-156, p.91 - 98, 2000/06
no abstracts in English
Petkov, P.*; Takeda, Toshikazu*; Mori, Takamasa
Annals of Nuclear Energy, 26(10), p.935 - 942, 1999/00
no abstracts in English
Kojima, Takuji; Tanaka, Ryuichi
Nihon Yakkyokuho Ni Junkyoshita Mekkinho Oyobi Biseibutsu Satsumetsuho, p.74 - 82, 1997/00
no abstracts in English
Togawa, Orihiko
Shinkokyu Kido Moderu; Gaiyo To Kaisetsu, 0, p.74 - 85, 1995/03
no abstracts in English
Kojima, Takuji; H.L.A.Ranjith*; Haruyama, Yasuyuki; Kashiwazaki, Shigeru*; Tanaka, Ryuichi
Applied Radiation and Isotopes, 44(1-2), p.41 - 45, 1993/00
Times Cited Count:12 Percentile:73.75(Chemistry, Inorganic & Nuclear)no abstracts in English
Mori, Takamasa; Nakagawa, Masayuki
Journal of Nuclear Science and Technology, 29(11), p.1061 - 1073, 1992/11
no abstracts in English
Ebinuma, Yukio
Int.Inf.Commun.Educ., 6(1), p.45 - 54, 1987/01
no abstracts in English
; ; ; Minato, Kazuo; ; Ikawa, Katsuichi
Nihon Genshiryoku Gakkai-Shi, 26(1), p.57 - 74, 1984/00
Times Cited Count:1 Percentile:18.93(Nuclear Science & Technology)no abstracts in English
JAERI-M 83-222, 38 Pages, 1983/12
no abstracts in English
Hoken Butsuri, 18(1), p.3 - 10, 1983/00
no abstracts in English