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Yamada, Katsunori; Fujii, Katsutoshi; Kanda, Hiroshi; Higashi, Daisuke; Kobayashi, Toshiaki; Nakagawa, Masahiro; Fukami, Tomoyo; Yoshida, Keisuke; Ueno, Yumi; Nakajima, Junya; et al.
JAEA-Review 2013-033, 51 Pages, 2013/12
JAEA-Review-2013-033.pdf:2.73MB
After the accident at Fukushima Dai-ichi Nuclear Power Plant, various numerical criteria relevant to radiation protection were defined. We surveyed these criteria through internet. As a result of survey, the following 13 items were identified: (1) criteria for taking stable iodine tablets, (2) criteria for the screening of surface contamination, (3) evacuation area, sheltering area, etc., (4) activity concentrations in food, drinking water, etc., (5) dose limit for radiation workers engaged in emergency work, (6) guideline levels of radioactive substances in bathing areas, (7) criteria for use of school buildings and schoolyards, (8) restriction on planting rice, (9) acceptable activity concentrations in feedstuff, (10) acceptable activity concentrations in compost, (11) criteria for export containers and ships, (12) criteria for contaminated waste, (13) standards for radiation workers engaged in decontamination work. In this report, the basis of and issues on these criteria are summarized.
Nakagawa, Masahiro; Nojima, Shun; Fujii, Katsutoshi; Shishido, Nobuhito; Sakai, Toshiya; Umehara, Takashi; Shimizu, Isamu
Hoken Butsuri, 47(3), p.189 - 193, 2012/10
It is essential to wear an air-purifying respirator in the radiation works in a contaminated atmosphere. A breath-responsive-powered air-purifying respirator (BR-PAPR) has been recently developed. However, no research has yet been conducted to determine the protection factor (PF) of the BR-PAPR in actual workplaces. In this study, the PFs of the BR-PAPR were measured by a man-test apparatus and compared with those of a non-powered full face mask. The PFs were measured under three different situations; normal wearing condition, clogging the filter and leaving a gap between the face and the mask. Under these situations, it was found that the PFs of the BR-PAPR are higher than those of the non-powered full face mask. PFs greater than 4000 were obtained for 95% of the subjects who wear the BR-PAPR, and PFs over 6667, the upper limit of the man-test apparatus, were obtained for 49% of them. The questionnaire survey was conducted for workers. The results showed that the workers feel a reduced burden when they wear the BR-PAPR. The results of this study showed high protection performance and operation efficiency of the BR-PAPR.
Sasaki, Satoru; Suto, Toshiyuki; Harada, Akio; Kurihara, Ryoichi; Yamamoto, Kazuyoshi; Tsuchida, Noboru; Shimizu, Isamu; Nomura, Toshibumi
Genshiryoku eye, 57(1), p.66 - 75, 2011/01
no abstracts in English
Shimizu, Takao*; Tamada, Masao; Seko, Noriaki; Sakaguchi, Isamu*
Kaiyo Kaihatsu Rombunshu, 18, p.737 - 742, 2002/06
Total amount of uranium in seawater is 4.5 billion tons corresponding to 45,000 times of annual demand for nuclear fuel in the world, though its concentration is only 3.3 mg/m3. The target of this study is that the cost-down of uranium collection from the sea to three times of the market price. This price is cheaper than the recycle fuel by nuclear reprocessing. The present study proposed a high performance adsorbent made by means of both radiation induced graft polymerization and braid technique. The drag force of the braid type adsorbent in water channel was measured. In the west coast of Okinawa prefecture, the adsorption of uranium and the adhesion of sea creature were investigated. It was clarified that reduction of the drag force by the deformed braid adsorbent in the water flow, the increment of uranium adsorption owing to high temperature of seawater, and little adhesion of the creature.
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discrimination in liquid scintillation measurementKuwabara, Jun; Shimizu, Isamu
Radioisotopes, 47(3), p.222 - 225, 1998/03
no abstracts in English
Taki, Mitsumasa; Kobayashi, Hideo; Suzuki, Takashi; Shimizu, Isamu
JAERI-M 90-206, 345 Pages, 1990/11
no abstracts in English
Onuma, Isamu; Kanamori, Kenji; Sekijima, Mitsuaki; Kobayashi, Makoto; Akiyama, Isamu; Shimizu, Isamu
no journal, ,
no abstracts in English
Onuma, Isamu; Kawasaki, Katsuya; Kowatari, Munehiko; Yasu, Katsuji; Okura, Takehisa; Kajimoto, Yoichi; Shimizu, Shigeru
no journal, ,
no abstracts in English
Takahashi, Teruhiko; Niinuma, Shinichi; Futagawa, Kazuo; Otsuka, Yoshikazu; Muto, Yasushi; Sakai, Toshiya; Umehara, Takashi; Shimizu, Isamu; Umino, Takaaki; Yamada, Satoshi; et al.
no journal, ,
no abstracts in English
Onuma, Isamu; Kobayashi, Makoto; Umehara, Takashi; Shimizu, Isamu
no journal, ,
no abstracts in English
Nakajima, Junya; Yokosuka, Yoshiyuki; Arakawa, Yuto; Shimizu, Isamu; Umehara, Takashi
no journal, ,
In NUCEF we monitor the radiation level continuously with 81 radiation monitors. Although these monitors are checked periodically, failures have occurred due to various reasons. Then we accumulated all monitor failures which had happened in recent 18 years, and categorized them by reason. This allowed us to find that the number of the failure much differs from monitor to monitor, and that there was a deviation between the reasons of the failure. After that, about degradation of GM tube used as dust monitor, which is by far the most of all reasons, we investigated the relation between the average cps and the interval of exchange. As a result, we couldn't find any causal relationship between the both. On the other hand, to improve the failure situation, we have exchanged expendables periodically, and furthermore, the result of the failure analysis should be fed back for better preventive maintenance.
Nakagawa, Masahiro; Nojima, Shun; Fujii, Katsutoshi; Shishido, Nobuhito; Sakai, Toshiya; Umehara, Takashi; Shimizu, Isamu
no journal, ,
no abstracts in English
Fujii, Katsutoshi; Takahashi, Teruhiko; Saegusa, Jun; Shishido, Nobuhito; Mochizuki, Kaoru*; Nojima, Shun; Akiyama, Isamu; Shimizu, Isamu
no journal, ,
In NSRR, pulse operation is performed. The correction of counting-loss is needed under the condition that large amount of neutrons have detected in a short period of time. This time, counting-loss of the neutron survey meter(type NSN1) is estimated used for monitoring Burst neutrons at NSRR.
Masuyama, Koichi; Arakawa, Yuto; Otsuka, Yoshikazu; Yokosuka, Yoshiyuki; Kobayashi, Makoto; Akiyama, Isamu; Shimizu, Isamu
no journal, ,
no abstracts in English
