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Okura, Takehisa; Oishi, Tetsuya; Taki, Mitsumasa; Shibanuma, Yukio; Kikuchi, Masamitsu; Akino, Hitoshi; Kikuta, Yasuaki; Kawasaki, Masatsugu; Saegusa, Jun; Tsutsumi, Masahiro; et al.
JAEA-Data/Code 2012-010, 37 Pages, 2012/05
JAEA-Data-Code-2012-010.pdf:2.28MB
Due to the accident at Fukushima Daiichi Nuclear Power Plant caused by the 2011 off the Pacific coast of Tohoku Earthquake occurred at 11th March 2011, the emergency environmental radiation monitoring was conducted at Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA). This report provides the monitoring results of ambient 
-ray dose rate and atmospheric radioactivity concentration until the beginning of June 2011. Some anthropogenic radionuclides such as Cs-134, Cs-137, I-131, I-132, Te-132, Xe-133 and others were detected from air samples. The atmospheric radioactivity concentrations varied with some peaks corresponded with that of ambient -ray dose rate after 15th March 2011. Composition of each peak showed various characteristic. Internal exposure caused by inhalation was estimated from the observed atmospheric radioactivity.
Shimizu, Shigeru; Sawahata, Tadahiro*; Kajimoto, Yoichi; Shikaze, Yoshiaki; Yoshihara, Yasuaki*; Tatebe, Yosuke
JAEA-Technology 2011-008, 53 Pages, 2011/06
JAEA-Technology-2011-008.pdf:2.91MB
The International Standard, ISO 4037-1, is applied worldwide for setting the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. X-ray reference fields were established at the Facility of Radiation Standard in Nuclear Science Research Institute in 2003 and had been operated. Recently, we rebuilt the X-ray reference fields by replacing the X-ray tube with a new model due to the damage of the old one of the middle-hard X-ray irradiation device. We have established three series of medium-hard X-ray reference fields, Narrow, Wide and High air-kerma series with 27 radiation qualities, based on ISO 4037-1. This article described quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalent from Air-kerma and comparison with the quality of ISO 4037-1 in the X-ray fields of medium-hard X-ray voltages ranging from 20 kV to 300 kV. Result of experiments, these X-ray reference fields were well agreed with the condition of the international standard. As a result, these X-ray reference fields were found to be used to carry out the performance test, standard irradiation based on the international standard, and an intercomparison experiment with the reference laboratories in the world.
Shimizu, Shigeru; Sawahata, Tadahiro; Kajimoto, Yoichi; Shikaze, Yoshiaki; Yoshihara, Yasuaki*; Tatebe, Yosuke
JAEA-Technology 2010-009, 78 Pages, 2010/06
JAEA-Technology-2010-009.pdf:3.06MB
In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. We renewed a X-ray tube of the medium-hard X-ray irradiation device that was damaged in the Facility of Radiation Standards in Nuclear Science Research Institute. Therefore, we established four series of medium-hard X-ray reference fields with quality index of 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this process, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalents from Air-kerma were evaluated in the medium-hard X-ray fields produced with X-ray tube voltage ranging from 20kV to 300kV. As a result, medium-hard X-ray reference fields were established that can provide the dose equivalent standard with good precision and wide range of test energy points and dose rates. We clarified these detailed data.
-ray efficiency curves for volume samples by the combination of Monte Carlo simulations and point source calibrationSaegusa, Jun; Oishi, Tetsuya; Kawasaki, Katsuya; Yoshizawa, Michio; Yoshida, Makoto; Sawahata, Tadahiro*; Honda, Tetsutaro*
Journal of Nuclear Science and Technology, 37(12), p.1075 - 1081, 2000/12
no abstracts in English
; Takahashi, Fumiaki; Sawahata, Tadahiro*; *; *; Murayama, Takashi
JAERI-Tech 99-004, 89 Pages, 1999/02
no abstracts in English
Tatebe, Yosuke; Onuma, Isamu; Kawasaki, Katsuya; Kowatari, Munehiko; Sawahata, Tadahiro; Sato, Yasuo; Yoshizawa, Michio
no journal, ,
no abstracts in English
