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-ray measurement due to air luminescence employing a liquid scintillation spectrometer*;
Nuclear Instruments and Methods, 159(1), p.139 - 143, 1979/00
no abstracts in English
Yasuda, Kenichiro; Suzuki, Daisuke; Kanazawa, Kazuhito; Miyamoto, Yutaka; Esaka, Fumitaka; Magara, Masaaki
no journal, ,
In order to detect of undeclared activities in nuclear facilities, we develop to technique of safeguards environmental sample analysis in JAEA. As part of this effort, isotope ratio analysis of individual MOX particle was performed using by TIMS without chemical treatment. It is possible to estimate an age determination of plutonium purification by a combination of the plutonium isotope ratios and (Pu-238+Am-241)/(Pu-239+Pu-240) alpha activity ratios were obtained by the alpha spectrometry. Since the plutonium particle size is more than 1
m due to the influence of self-absorption, exactly measurement of the activity ratios has been difficult. Therefore, we were examining how to acid dissolution in the plutonium particles on the TIMS filament before alpha spectrometry.
Onishi, Takashi; Tanaka, Kosuke; Sato, Isamu*; Ishikawa, Takashi; Hirosawa, Takashi; Katsuyama, Kozo; Seino, Hiroshi; Ohno, Shuji; Hamada, Hirotsugu; Tokoro, Daishiro*; et al.
no journal, ,
no abstracts in English
Tsubota, Yoichi; Honda, Fumiya; Nakagawa, Takahiro; Kawasaki, Takashi; Ikeda, Atsushi; Tamakuma, Yuki*; Tokonami, Shinji*; Momose, Takumaro
no journal, ,
A large number of radioactive aerosols, especially alpha particles, are expected to be generated during fuel debris retrieval on Fukushima - Daiichi (1F) site and decommissioning of nuclear fuel cycle facilities. For conventional alpha dust monitor, 1-channel of silicon surface barrier detector (SSBD) is often used as a detector which has not so high limit of count rates. Moreover, since radioactive aerosol collected on a filter paper are measured by a detector, it is difficult to calculate an airborne concentration at the sampling site because a conventional dust monitor measures an integrated radioactivity on a filter paper. In this work, we developed a prototype of alpha dust monitor aiming at an in-situ measurement of high concentration airborne alpha particles. The efficiency for U
O
checking source was 80.8%. For high count rate test using 3 MBq of 
Am checking source, 2.1 
10
cpm was achieved which was more than 10 times higher compared to an conventional alpha dust monitor using SSBD. For follow-up test to the airborne concentration of alpha particles using radon chamber, counting rate of prototype alpha dust monitor was smoothly followed with respect to the radon concentration in a radon chamber.