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Endo, Akira
Radiation Protection Dosimetry, 175(3), p.378 - 387, 2017/07
Times Cited Count：11 Percentile：72.2(Environmental Sciences)The International Commission on Radiation Units and Measurements (ICRU) has been discussing to propose a new system of the operational quantities for external radiations based on protection quantities. The aim of this study is to provide a set of conversion coefficients for use in defining personal dose equivalent for individual monitoring. Fluence-to-effective dose conversion coefficients have been calculated for photons, neutrons, electrons, positrons, protons, muons, pions and helium ions for various incident angles of radiations. The data sets comprise effective dose conversion coefficients for incident angles of radiations from 0 
to 90 in steps of 15 and at 180. Conversion coefficients for rotational, isotropic, superior hemisphere semi-isotropic and inferior hemisphere semi-isotropic irradiations are also included. The conversion coefficients are used to define the operational quantity personal dose equivalent which is being considered by ICRU and utilized for the design and calibration of dosemeters.
rays and the exposure dosesSaito, Kimiaki; Endo, Akira
Radioisotopes, 63(12), p.585 - 602, 2014/12
The article provides the fundamental information necessary for the appropriate evaluation of exposure doses in the environment. The basic characteristics of environmental rays from typical environmental sources are introduced; then, the dose conversion coeffcients for the public at different ages are summarized which were obtained from the simulation considering the basic characteristics of environmental rays. Further, the variations of environmental exposure doses due to a variety of factors, and the relation of exposure doses to measured air dose rates are discussed.
Tran, V. H.; Satoh, Daiki; Takahashi, Fumiaki; Tsuda, Shuichi; Endo, Akira; Saito, Kimiaki; Yamaguchi, Yasuhiro
JAERI-Tech 2004-079, 37 Pages, 2005/02
JAERI-Tech-2004-079.pdf:5.02MB
no abstracts in English
Shelley, A.; Kugo, Teruhiko; Shimada, Shoichiro*; Okubo, Tsutomu; Iwamura, Takamichi
JAERI-Research 2004-002, 47 Pages, 2004/03
JAERI-Research-2004-002.pdf:3.08MB
Neutronic study has been done for a PWR-type reduced-moderation water reactor with seed-blanket fuel assemblies to achieve a high conversion ratio, a negative void coefficient and a high burnup by using a MOX fuel. The results of the precise assembly burnup calculations show that the recommended numbers of seed and blanket layers are 15(S15) and 5(B5), respectively. By the optimization of axial configuration, the S15B5 assembly with the seed of 1000
2 mm high, internal blanket of 150 mm high and axial blanket of 4002 mm high is recommended. In this configuration, the conversion ratio is 1.0 and the core average burnup is 38 GWd/t. The S15B5 assembly can attain the core average burnup of 45 GWd/t by decreasing the height of seed to 5002 mm, however, the conversion ratio becomes 0.97. The void and fuel temperature coefficients are negative for both of the configurations. Effect of metal or T-MOX (PuO
+ThO) fuel has been also investigated. Metal improves the conversion ratio but makes the void coefficient worse. T-MOX improves the void coefficient, but decreases the conversion ratio.
Sato, Tatsuhiko; Tsuda, Shuichi; Sakamoto, Yukio; Yamaguchi, Yasuhiro; Niita, Koji*
Radiation Protection Dosimetry, 106(2), p.137 - 144, 2003/11
Times Cited Count：19 Percentile：75.71(Environmental Sciences)Radiological protection against high energy heavy ions has been an essential issue in the planning of long-term space missions. We calculated fluence to effective dose conversion coefficients for heavy ions using the Particle and Heavy Ion Transport code System PHITS coupled with an anthropomorphic phantom of the MIRD5 type. The calculations were performed for incidences of protons and typical space heavy ions with energies up to 3 GeV/A in the isotropic and anterior-posterior irradiations. Based on the results, we propose a simple fitting formula that can predict the effective dose from almost all kinds of space heavy ions below 3 GeV/A within an accuracy of 30%.
Shelley, A.; Shimada, Shoichiro*; Kugo, Teruhiko; Okubo, Tsutomu; Iwamura, Takamichi
Nuclear Engineering and Design, 224(3), p.265 - 278, 2003/10
Times Cited Count：15 Percentile：66.87(Nuclear Science & Technology)Parametric studies have been done for a PWR-type reduced-moderation water reactor (RMWR) with seed-blanket fuel assembles to achieve a high conversion ratio, negative void reactivity coefficient and a high burnup. It was found that 50 to 60% of seed in a seed-blanket assembly has higher conversion ratio. The number of seed-blanket layers is 20, in which the number of seed layers is 15 and blanket layers is 5. The fuel assembly with the height of seed of 1000mm2, internal blanket of 150 mm and axial blanket of 400mm2 is recommended. The conversion ratio is 1.0 and the average burnup in core region is 38.2 GWd/t. The enrichment of fissile Pu is 14.6 wt%. The void coefficient is +21.8 pcm/% void, however, it is expected that the void coefficient will be negative if the radial neutron leakage is taken into account. It is also possible to use this fuel assembly for a high core averaged burnup of 45GWd/t, however, the height of seed must be 500mm2 to improve the void coefficient. The conversion ratio is 0.97 and void coefficient is +20.8 pcm/%void.
Raman, S.*; Nestor Jr., C. W.*; Ichihara, Akira; Trzhaskovskaya, M. B.*
Physical Review C, 66(4), p.044312_1 - 044312_23, 2002/10
Times Cited Count：52 Percentile：89.76(Physics, Nuclear)no abstracts in English
Sasamoto, Nobuo; Nakashima, Hiroshi; Hirayama, Hideo*; Shibata, Tokushi*
Journal of Nuclear Science and Technology, 39(Suppl.2), p.1264 - 1267, 2002/08
no abstracts in English
Okubo, Tsutomu; Takeda, Renzo*; Iwamura, Takamichi; Yamamoto, Kazuhiko*; Okada, Hiroyuki*
Proceedings of International Conference on Back-End of the Fuel Cycle: From Research to Solutions (GLOBAL 2001) (CD-ROM), 7 Pages, 2001/09
An advanced water-cooled reactor concept named the Reduced-Moderation Water Reactor (RMWR) has been proposed to attain a high conversion ratio more than 1.0 and to achieve the negative void reactivity coefficient. At present, several types of design concepts satisfying both the design targets have been proposed based on the evaluation for the fuel without fission products and minor actinides. In this paper, the feasibility of the RMWR core is investigated and confirmed for the plutonium multiple recycling under advanced reprocessing schemes with low decontamination factors as proposed for the FBR fuel cycle.
Sakamoto, Yukio; Yamaguchi, Yasuhiro
JAERI-Tech 2001-042, 29 Pages, 2001/06
JAERI-Tech-2001-042.pdf:1.79MB
no abstracts in English
Murata, Mikio; Noguchi, Hiroshi
Nihon Genshiryoku Gakkai-Shi, 34(2), p.149 - 152, 1992/02
Times Cited Count：2 Percentile：43.73(Nuclear Science & Technology)no abstracts in English
C-J.Jeong*; Okumura, Keisuke; ; Tanaka, Kenichi*
Journal of Nuclear Science and Technology, 27(6), p.515 - 523, 1990/06
no abstracts in English
; ;
Nihon Genshiryoku Gakkai-Shi, 23(10), p.762 - 771, 1981/00
Times Cited Count：1 Percentile：24.39(Nuclear Science & Technology)no abstracts in English
; ; ;
Journal of Nuclear Science and Technology, 17(3), p.225 - 240, 1980/00
Times Cited Count：2 Percentile：33.82(Nuclear Science & Technology)no abstracts in English
