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Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
Journal of Nuclear Science and Technology, 59(5), p.656 - 664, 2022/05
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)It is known that internal doses depend on the physical characteristics of an evaluation subject. Internal dose coefficients provided by the International Commission on Radiological Protection (ICRP) are evaluated using the characteristics of the standard Caucasian. It is important to grasp the variations of doses due to the differences in characteristics between Japanese and Caucasian when the dose coefficients of ICRP are applied to Japanese. This study evaluated dose coefficients using specific absorbed fraction (SAF) data based on the average adult Japanese physique which was developed by modification of the existing Japanese SAF data with additional calculations to make the existing data fit to the current dosimetric methodology of ICRP and compared them to those provided by ICRP. As a result, the discrepancies in dose coefficients were smaller than plus or minus 10% in most intake conditions. However, some intake conditions indicated varieties over 40% due to the differences in organ masses, amount of adipose tissues around the thoracic cavity, and so on. This information is useful in application of ICRP's dose coefficients to population of which physical characteristics are different from those of Caucasian. Further, the Japanese SAF data is published as an appendix of this paper.
3(111) symmetrical tilt grain boundary in 
-ironEbihara, Kenichi; Suzudo, Tomoaki
Modelling and Simulation in Materials Science and Engineering, 26(6), p.065005_1 - 065005_10, 2018/09
Times Cited Count：4 Percentile：19.87(Materials Science, Multidisciplinary)Irradiation-induced grain boundary phosphorus segregation is an important factor for estimating the embrittlement of nuclear reactor pressure vessel steels, but the physical process of phosphorus migration to grain boundaries is still unclear. We numerically studied phosphorus migration toward 3(111) symmetrical tilt grain boundary in -iron using molecular dynamics. We found that, in the vicinity of the grain boundary within 
1 nm distance, an iron-phosphorus mixed dumbbell and an octahedral interstitial phosphorus atom push a self-interstitial atom into the grain boundary, and the phosphorus atom becomes a substitutional atom. A phosphorus vacancy complex in the region also becomes dissociated, and the vacancy is absorbed in the grain boundary without dragging phosphorus. The results claim that a novel view of the segregation process is required.
Sato, Kaoru; Takahashi, Fumiaki
Hoken Butsuri, 52(4), p.247 - 258, 2017/12
Organ doses for dose assessment in radiation protection are derived from ICRP reference phantoms (Male:RCP-AM, Female:RCP-AF) with standard Caucasian physiques. In adult, Japanese are smaller than Caucasian. To study impact of differences in physiques between Caucasian and Japanese on organ doses, we previously constructed Japanese phantoms (Male:JM-103, Female:JF-103) with average adult Japanese physiques. In addition, adult Japanese physiques have also wide distribution. Thus, we newly modeled DJM (Male) and DJF (Female) with 8 physiques by changing the perimeters of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV, it was found that doses of breast, colon, lung, stomach, gonad, urinary bladder, esophagus, liver and thyroid in DJM and DJF with physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10%.
Ebihara, Kenichi; Watanabe, Tadashi
Nihon Kikai Gakkai Dai-14-Kai Keisan Rikigaku Koenkai Koen Rombunshu, p.579 - 580, 2001/11
no abstracts in English
Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP reference phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese body physiques are smaller than those of Caucasian. To study impact of application of organ doses of RCP-AM and RCP-AF to dose assessment of adult Japanese, we constructed Japanese male (JM-103) and female (JF-103) phantoms with body physiques of average adult Japanese. In addition, body physiques of adult Japanese have also wide distribution. Therefore, we newly constructed DJM (Male) and DJF (Female) with 8 body physiques by changing bust, chest, waist and hip of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV and ROT geometry at 0.6 MeV, it was found that colon doses of DJM and DJF with body physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10 %.
Sato, Kaoru; Takahashi, Fumiaki; Koba, Yusuke*; Ono, Koji*; Yoshitake, Takayasu*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Kasahara, Tetsuji*; Okuda, Yasuo*; Nakada, Yoshihiro*; et al.
no journal, ,
JAEA is now developing CT dose calculator named WAZA-ARIv2 in cooperation with the National Institute of Radiological Sciences. WAZA-ARIv2 has been opened to the public as full-dress uses on January 2015. WAZA-ARIv2 can perform dose assessment against 4 different body physiques by using the organ dose database, which were constructed on the basis of adult Japanese phantoms with 4 body sizes (-2
, average, +2, +5). In this study, it was found that salivary gland doses are independent on BMI, whereas lung doses are dependent on BMI. The differences in the effects of BMI on absorbed doses between salivary glands and lungs might be caused by the difference in thickness of subcutaneous soft tissues between head and thorax.
Sato, Kaoru; Takahashi, Fumiaki; Koba, Yusuke*; Ono, Koji*; Yoshitake, Takayasu*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Kasahara, Tetsuji*; Okuda, Yasuo*; Nakada, Yoshihiro*; et al.
no journal, ,
WAZA-ARIv2 is developed as the web-based open system for CT dose calculator under joint research of JAEA, NIRS (now, QST) and Oita University of Nursing and Health Sciences. WAZA-ARIv2 can provide organ doses under consideration of the body physiques (BMI = 18, 22, 28, 37) of patients with average height of adult Japanese by using voxel phantoms developed by JAEA. In this study, we analyzed the relationship between variations of organ doses and body indices. It was found that effects of weight variations on organ doses were larger than those of height variations. Generally, thickness of the subcutaneous soft tissues is easily changed by variations of weight rather than those of height. This fact may cause the differences in variations of organ doses between weight and height.
Sato, Kaoru; Satoh, Daiki; Takahashi, Fumiaki; Furuta, Takuya
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese have small size body, compared with Caucasian. Considering the physiques of Japanese is very important, when organ doses of RCP-AM and RCP-AF are applicable for constructing of radiation protection standard in Japan. So far, we reported the dosimetric characteristics of adult Japanese with various body sizes, which were irradiated with photons. In this study, we analyzed the impact of body sizes on organ doses due to external neutron irradiation. In analysis, we utilized the male and female phantoms with 3 body physiques by changing busts, chests, waists and hips of JM-103 and JF-103. In rotational geometry at 3 MeV, it was found that colon doses of adult Japanese phantoms with body sizes, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 20%.
Sato, Kaoru; Furuta, Takuya; Takahashi, Fumiaki
no journal, ,
We are now developing adult Japanese polygon human models (male: JPM and female: JPF) for the purposes of dose assessment of Japanese. At the 2nd joint annual research meeting of JHPS and JRSM, overviews of development of these human models were presented. Thereafter, we performed the improving of the posture change functions and averaging of organ masses and body sizes. In this presentation, we will introduce and explain about the characteristics of posture change functions and physiques of JPM and JPF. In addition, we will show test calculation results of organ doses under various postures.
