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Sagawa, Naoki; Izaki, Kenji; Mizuniwa, Harumi*
JAEA-Technology 2013-029, 28 Pages, 2013/11
JAEA-Technology-2013-029.pdf:3.35MB
Developed in the Mixed Oxide fuel fabrication facility, Basic handling of IP, analysis method, detection of Pu and radioactivity quantification. These are the conditions that the exposure conditions and the analysis condition are constant. However, in the case of Contamination has occurred in the workplace, contaminated samples are not only Pu. It may contain a Pb or RnTn. Then, if other work is being carried out in a room that is the operation of IP, it's difficult to darken the room. PSL is reduced when light hits the IP. In this study, we have investigated in order to upgrade radiation protection, in the case of Containing the Pb or PSL reduction by light. Additionally, regarding change of analysis condition, the analysis method was examined when the resolution was changed to 50 micro, 100 micro and 200 micro.
Takasaki, Koji; Sagawa, Naoki; Kurosawa, Shigeyuki; Mizuniwa, Harumi
Journal of Nuclear Science and Technology, 48(6), p.911 - 918, 2011/06
Times Cited Count：11 Percentile：64.69(Nuclear Science & Technology)An autoradiographical method using an imaging plate (IP) was developed to analyze the plutonium contamination in the plutonium handling facility and was applied to the monitoring of the workplace in a practical uranium-plutonium mixed oxide (MOX) fuel fabrication facility. A good relationship between the photo stimulated luminescence (PSL) intensities of IP and radioactivities measured by a radiation counter was obtained by the least-square fitting, taking the fading effect into consideration. The 
-radioactivities of plutonium contamination were derived from the PSL image in this IP method, and their relative errors were evaluated from exposure time.
Sagawa, Naoki; Yamazaki, Takumi; Kurosawa, Shigeyuki*; Izaki, Kenji; Mizuniwa, Harumi; Takasaki, Koji
JAEA-Technology 2010-051, 35 Pages, 2011/03
JAEA-Technology-2010-051.pdf:1.83MB
The image analysis method using a imaging plate (IP) is recent technique, and this method can get the information of radioactivity distribution by the unit of Photo Simulated Luminescence (PSL). We have investigated the PSL images obtained by measuring some plutonium samples which are radiation protection samples in order to apply imaging plate to the radiation protection at the MOX fuel facility. Plutonium spots were extracted from the PSL image extracted by the threshold, in which about 99% of the back ground was excluded, and identified by the additional requirement that the spot size is more than 40 pixels. The average background is subtracted from PSL strength of the spot area identified as Pu, and the radioactivity of the Pu spot was evaluated by multiplying the conversion calculation that is in consideration of fading.
Takasaki, Koji; Sagawa, Naoki; Kurosawa, Shigeyuki*; Shioya, Satoshi; Suzuki, Kazunori; Horikoshi, Yoshinori; Mizuniwa, Harumi
JAEA-Technology 2008-028, 73 Pages, 2008/03
JAEA-Technology-2008-028.pdf:5.88MB
Recently, an imaging plate (IP) was developed. Pu analysis by an IP was studied in the JAEA Cooperative Research Scheme on the Nuclear Fuel Cycle, and the availability about detection of Pu and discrimination with radon progenies was shown. In order to apply these results to the radiation control, this research aims at evaluation of radioactivity, discrimination with radon progenies, and evaluation of AMAD by an IP. In the conventional autoradiography (ARG) by a ZnS and Polaroid film, Contamination of Pu can only be grasped by viewing. Since the digital data of the radiation and location is obtained by an IP, Pu can be detected quantitatively and radioactivity can be evaluated. As a result of this research, the image of alpha emitter on an IP is the same as that of the conventional ARG, and can be applied also to the ARG of beta and 
emitter. In measurement of Pu, the function of Image J (image-analysis software) was very available. Pu radioactivity was evaluated by an IP.
Takaya, Akikazu; Mizuniwa, Naoki; Tanabe, Yoji; Sato, Soichi; Inano, Masatoshi
no journal, ,
no abstracts in English
Mizuniwa, Harumi; Takasaki, Koji; Horikoshi, Yoshinori; Suzuki, Kazunori; Shioya, Satoshi; Sagawa, Naoki; Kurosawa, Shigeyuki*
no journal, ,
no abstracts in English
Sagawa, Naoki; Kurosawa, Shigeyuki*; Takasaki, Koji; Mizuniwa, Harumi
no journal, ,
no abstracts in English
Yamazaki, Takumi; Sagawa, Naoki; Izaki, Kenji; Mizuniwa, Harumi
no journal, ,
no abstracts in English
Sagawa, Naoki; Odano, Takayuki*; Morifuji, Masayuki; Izaki, Kenji; Mizuniwa, Harumi
no journal, ,
no abstracts in English
Morishita, Yuki; Sagawa, Naoki; Tsubaki, Hirohiko; Izaki, Kenji; Mizuniwa, Harumi
no journal, ,
no abstracts in English
