文献一覧: 阪上正信 (著者)

7 0 0 0 OA リン鉱石およびリン酸肥料中のウラン, トリウム, カリウム含有量とウラン系列, トリウム系列核種の放射平衡

著者: 小村和久柳沢美樹男桜井次郎阪上正信
出版者: 公益社団法人日本アイソトープ協会
雑誌: RADIOISOTOPES (ISSN:00338303)
巻号頁・発行日: vol.34, no.10, pp.529-536, 1985-10-15 (Released:2010-12-13)
参考文献数: 17
被引用文献数: 3 11

2種のリン鉱石および市販の7種のリン酸肥料 (複合肥料も含む) についてウラン, トリウム, カリウム含有量とウラン系列, トリウム系列核種の放射平衡の状態について測定した。コラ産のリン鉱石以外の試料のウラン含有量は39-117ppmと高く, ウラン系列核種はほぼ放射平衡のものから著しく非平衡のものまで存在することが分かった。平衡の状態を, (1) 放射平衡かこれに近いもの, (2) 238U≈230Th>210Pb>226Ra, (3) 238U>230Th>210Pb>226Raのもの3つに分類して検討した。トリウム系列核種はほぼ放射平衡で含有量も一般に低く, 複合肥料以外はカリウム (K2O) 含有量は0.3%以下であった。これらの測定結果をもとにリン鉱石, リン酸肥料による放射線被曝についても検討した。

2021-03-29 08:44:32
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6 0 0 0 OA The Determination of Plutonium in Soil Samples

著者: 井上義和阪上正信
出版者: Journal of Radiation Research 編集委員会
雑誌: Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日: vol.11, no.2, pp.98-106, 1970-08-01 (Released:2006-08-29)
参考文献数: 13
被引用文献数: 5 6

The contents of plutonium-239 in soil were determined by using 238Pu as yield tracer. The samples were decomposed by nitric acid treatment under ultrasonic vibration and the separation of plutonium from other elements was carried out by using anion exchange resin. The surface soils showed the plutonium content of about 1 ?? 4 mCi/km2 and their 239Pu/90Sr activity ratios were 2 ?? 5%. From these results, it was concluded that 239Pu in soil at present was brought mainly by the fall-out due to the nuclear bomb test explosion.

2012-10-22 11:01:06
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4 0 0 0 OA トリチウムの環境動態

著者: 阪上正信
出版者: 社団法人プラズマ・核融合学会
雑誌: 核融合研究 (ISSN:04512375)
巻号頁・発行日: vol.54, no.5, pp.498-511, 1985-11-20 (Released:2011-03-04)
参考文献数: 10
被引用文献数: 1 1

Various studies about the behavior of tritium in the environment are reviewed with comments on several origins of their occurances. For atmospheric tritium, different chemical species and their seasonal variation have been studied. The average tritium concentration in river waters was found to be 1.5-2 times higher than that of precipitations at various sites of Japan.The vertical distribution of tritium in ground water has raised an interest for the samples collected from different wells in depth. The effect of the accidental release of tritium and the tritium level around nuclear facilities are also mentioned.

2023-09-05 20:41:30
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3 0 0 0 OA 富山におけるチェルノブイリ原発事故の影響

著者: 守田美雪庄司美樹本田昂阪上正信
出版者: 公益社団法人日本アイソトープ協会
雑誌: RADIOISOTOPES (ISSN:00338303)
巻号頁・発行日: vol.36, no.6, pp.282-285, 1987-06-15 (Released:2010-09-07)
参考文献数: 11
被引用文献数: 2 2

The environmental radioactivity caused by the reactor accident at Chernobyl'was investigated from May 7 to May 31 of 1986 in Toyama. Measurement of radioactivities in airborne particles, rain water, drinking water, milk, and mugwort are carried out by gamma-ray spectrometry (pure Ge detector; ORTEC GMX-23195) . Ten different nuclides (103Ru, 106R, 131I, 132Te-I, 134Cs, 136Cs, 137Cs, 140Ba-La) are identified from samples of airborne particles. In the air samples, a maximum radioactivity concentration of each nuclide is observed on 13th May 1986. The time of the reactor shut-down and the flux of thermal neutron at the reactor were calculated from 131I/132I and 137Cs/134Cs ratio.The exposure dose in Toyama by this accident is given as follows: internal exposure; [thyroid] adult-59 μSv, child-140 μSv, baby-130 μSv, [total body] adult-0.2 μSv, child, baby-0.4μSv, external exposure; 7 μSv, effective dose equivalent; adult-9μSv, child-12 μSv, baby-11 μSv.