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Kamwang, N.*; Kowatari, Munehiko; Yoshitomi, Hiroshi
Proceedings of 4th Asian and Oceanic Congress on Radiation Protection (AOCRP-4) (CD-ROM), 4 Pages, 2015/07
Yoshitomi, Hiroshi; Kowatari, Munehiko; Suzuki, Takashi
Proceedings of 4th Asian and Oceanic Congress on Radiation Protection (AOCRP-4) (CD-ROM), 4 Pages, 2015/07
The Facility of Radiation Standards (FRS) in the Japan Atomic Energy Agency (JAEA) provides beta-ray calibration fields for the customers to calibrate dosemeters. Two different types of beta-ray irradiation systems, so called BSS2 and JBS, have been installed and operated in the FRS. They have quite different types of the beta-ray radiation sources, which might be attributed to variations in dosimetric quantities. Variations in these quantities would affect the calibration factor of a dosemeter. A comparison of dosimetric quantities for beta reference radiation fields of both beta-ray irradiation systems was made, in order to investigate how these quantities differ between them and how much differences affect calibration results. With regard to the depth dose curve which is one of the key dosimetric quantities, it was found that they showed different profiles between both systems reflecting their characteristics. This implies that the difference between two systems might affect the calibration of dosemeters, especially one with more than 400 mg/cm
thickness or one made of high-Z materials for 
Sr/Y field.
Yoshitomi, Hiroshi; Tanimura, Yoshihiko*; Tatebe, Yosuke; Tsutsumi, Masahiro; Kawasaki, Katsuya; Kowatari, Munehiko; Yoshizawa, Michio; Shimizu, Shigeru*; Kim, J.-S.*; Lee, J.-G.*; et al.
Proceedings of 4th Asian and Oceanic Congress on Radiation Protection (AOCRP-4) (CD-ROM), 4 Pages, 2015/07
Usui, Toshihide; Takashima, Hideki; Iwasa, Atsutoshi; Hamazaki, Masaaki
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
Okura, Takehisa; Yamazawa, Hiromi*; Moriizumi, Jun*; Hirao, Shigekazu*; Guo, Q.*; Tojima, Yasunori*; Iida, Takao*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
Monitoring network of 
Rn concentration in air which was measured in Beijing, Nagoya, Hegura-jima, Hachijo-jima and Hateruma-jima, as a tracer for long-range transport in East Asia was established. At inland sites, Beijing and Nagoya, high concentrations Rn were measured, at marine sites, Hachijo-jima and Hateruma-jima, Rn concentrations level was very low. Seasonal variations of the Rn concentration show that Rn concentration was the lowest in the summer and the highest in the winter. Diurnal variations were measured at inland sites. At marine sites several-day-cycle variations were measured. It was pointed out by this study that the several-day-cycle variations at Hachijo-jima were dependent on synoptic-scale atmospheric disturbance. Backward trajectory analysis of the relationship between atmospheric Rn concentrations at Hachijo-jima and transport pathway of air mass indicates that atmospheric Rn at Hachijo-jima has much to do with transport pathway of air.
Yoshida, Tadayoshi; Tsujimura, Norio; Yamano, Toshiya*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
A neutron survey meter with a ZnS(Ag) scintillator to measure recoil protons was built. The detection probe weighs approx. 2 kg, therefore providing us with true portability. Performance tests exhibited satisfactory neutron dosimetry characteristics at unmoderated or lightly moderated fission neutron fields and in particular work environments at a MOX fuel facility. This new survey meter will augment a routine neutron monitoring inconveniently being carried out by moderator-based neutron survey meters.
Tsujimura, Norio; Yoshida, Tadayoshi; Takada, Chie
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
To predict how accurately the neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the calculations of the dose equivalent responses of neutron dosemeters were performed by the spectral folding method. The dosemeters selected included two types of personal dosemeters (a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter), three moderator-based neutron survey meters and one special instrument called an 
(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variation observed in neutron fields at workplaces.
Takeyasu, Masanori; Nakano, Masanao; Sumiya, Shuichi; Nemoto, Hiromi*; Kanno, Mitsuhiro*; Kurosawa, Naohiro*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 4 Pages, 2010/05
The dose to the public at hypothetical accident of nuclear facility is estimated on the basis of the method described in the Japanese meteorological guideline. However, the radioactive decay during atmospheric dispersion of released radionuclide is not considered in the calculation formula in the guideline. Therefore, when the radionuclide of the half life such as a few min is released, the dose may be excessively over-estimated. In this study, the calculation code was developed which could consider the radioactive decay of the released radionuclide and the generation of the product. The dose calculated on the basis of the developed code was compared with that on the basis of the guideline.
Kanai, Katsuta; Kurihara, Osamu
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
Chest wall thickness (CWT) of the subject is an important modifier to determine the lung burden of inhaled actinides such as Pu isotopes or 
Am through lung counting. CWT prediction equations as a function of biometric indexes have been proposed by many authors based on chest wall measurements made with an ultrasound device. In the present study we derived such equations from CWT data of our subjects and then evaluated their applicability to monitoring with our currently used lung counter, mainly examining the accuracy of determinations of Am, useful as a unique indicator that can be detected in most cases of internal contamination with Pu compounds. The error of the equations obtained was found to be within the range of - 8 mm to + 6 mm against actual CWT values of our subjects, complying with the bias performance criteria for direct measurements. However, further studies might be needed to clarify the effect of the difference in posture on the CWT caused by the modification of the counting geometry made for our lung counter.
Mohammadi, A.; Kinase, Sakae
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM), 3 Pages, 2010/05
Kinase, Sakae; Noguchi, Hiroshi; Sakamoto, Yukio; Nakamura, Takashi*; Kimura, Masaya*
Proceedings of 1st Asian and Oceanic Congress for Radiation Protection (AOCRP-1) (CD-ROM), 10 Pages, 2002/10
It is necessary to develop suitable tissue substitutes for the respiratory tract phantom. In the present study, optimum amounts of additive in the base materials were calculated in accordance with the basic data method. On the basis of the method, tissue substitutes with high mass density were made on an experimental basis. The substitutes were examined for the photon transmissions using 16.6 keV K-Xrays from Nb-93m and 59.5 keV gamma-rays from Am-241. It was found that the experimental transmission curves of the tissue substitutes are in good agreement with the calculated ones. Furthermore, mass attenuation coefficients for the tissue substitutes of the JAERI torso phantom were evaluated. It was found that the tissue substitutes are suitable as phantom materials and can simulate the body tissues defined in ICRP Publication.23.
ray detection systemsOishi, Tetsuya; Tsutsumi, Masahiro; Sugita, Takeshi*; Yoshida, Makoto
Proceedings of 1st Asian and Oceanic Congress for Radiation Protection (AOCRP-1) (CD-ROM), 9 Pages, 2002/10
An EGS4 user code has been developed to design gamma ray detection systems for complex shapes of radioactive sources. The code is fundamentally based on the PRESTA-CG, which is improved on the electron transport in the EGS4 and specialized for using a combinatorial geometry (CG) method. The newly added functions are classified mainly into two parts of the transport of particles and the definition of sources. This user code was applied to some detectors used for low-level radioactive wastes monitoring in order to demonstrate the availability of this code. As the result, it was found that the response of anti-Compton spectrometer and the radiation background in a concrete building could be suitably estimated.
Tachibana, Haruo; Yamaguchi, Takenori; Matsuoka, Shungo*; Nemoto, Shintaro*; Kurosawa, Naohiro*
Proceedings of 1st Asian and Oceanic Congress for Radiation Protection (AOCRP-1) (CD-ROM), 7 Pages, 2002/10
An environmental radiation monitoring system in Tokai establishment of JAERI is composed of 14 monitoring posts, 4 monitoring stations, 2 drainage monitors and the monitoring data observation center. These monitoring posts and stations measure the gamma dose rate, and the monitoring stations measure the radioactive air concentration too. Drainage monitors measure the radioactive concentration in drain water. We developed the environmental radiation dose information system used by cellular phone for observing the monitoring data in day and night, working day and holiday at everyplace in Japan. This information system shows us the every minute or every 10 minutes monitoring data table and data trend graph on the cellular phone display. In the emergency situation, this system helps for speedy response such as the notification to the JAERI staffs, starting the emergency environmental monitoring activities, reporting the dose rate and concentration to the national and local authorities, and establishment of the emergency response team in JAERI.
; Sato, Haruo
P.101(OP8B-4)(2002), 101 Pages, 2002/00
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Takada, Chie; ; Hozumi, Toshihiko; Hashimoto, Makoto
Proceedings of 1st Asian and Oceanic Congress for Radiation Protection (AOCRP-1) (CD-ROM), p.20 - 24, 2002/00
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; Takeishi, Minoru
T-6C-3, 0 Pages, 2002/00
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; Sato, Haruo
The 1st Asian and Oceanic Congress for Radiation P, 0 Pages, 2002/00
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Koarashi, Jun; Miyabe, Kenjiro; Mikami, Satoshi
The First Asian and Oceanic Congress for Radiation Protection, 0 Pages, 2002/00
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Ishida, Junichiro; Takahashi, Keizo; Nomura, Tamotsu
The First Asian and Oceanic Congress for Radiation Protection (AOCRP-1), 0 Pages, 2002/00
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