DISTRIBUTION OF LOCAL FALLOUT FROM THE HIROSHIMA A-BOMB - ANALYSIS OF U-235/U-238 RATIO

广岛原子弹局部放射性尘埃分布 - U-235/U-238 比率分析

• 批准号: 13680624
• 负责人: FUJIKAWA Yoko
• 金额: $ 2.05万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680624/
• 关键词: URANIUM; HIROSHIMA A-BOMB; ISOTOPE RATIO; LOCAL FALOUT

Contents of black rain from the A-bomb are important to clarify the health and environmental hazard caused by nuclear warfare. We analyzed the only existing physical remains of the black rain from Hiroshima A-bomb (Little Boy), a plastered wall with black streaks. Excess ^<137>Cs and anomalous ^<235>U/^<238>U ratios detected in the black residues on the wall confirmed that the black streaks on the wall originated from Little Boy. The results also showed that excess ^<235>U could be used as a fingerprint to clarify the distribution of materials discharged from Little Boy into the environment. High concentrations of Pb and Zn, which may have caused a degree of heavy metal pollution in the area where the rain fell, were also detected in the black rain sample..Deviation in U-235/U-238 isotope ratio from natural ratio, on the other hand, was not found in soil collected three days after A-bomb detonation in Hiroshima, where approximately 50 kg of U-235 should have been discharged. U-234/U-238 ratio variation in soil that was dependent on the soil particle size and soil digestion procedure was found.

原子弹黑雨的成分对于阐明核战争对人类健康和环境的危害具有重要意义。我们分析了广岛原子弹（小男孩）留下的黑雨的唯一实物遗迹，一堵有黑色条纹的石膏墙。在墙壁上的黑色残留物中检测到过量的^<137>Cs和异常的^<235>U/^<238>U比率，证实了墙壁上的黑色条纹来自小男孩。结果还表明，过量的^<235>U可以作为指纹，以澄清从小男孩排放到环境中的物质的分布。在黑雨样品中还检测到高浓度的Pb和Zn，这可能导致降雨区域的重金属污染。另一方面，在广岛原子弹爆炸后三天收集的土壤中，未发现铀235/铀238同位素比偏离自然比率的情况，而在广岛原子弹爆炸后三天，应该有大约50公斤的铀235被释放。土壤中U-234/U-238比值的变化取决于土壤颗粒大小和土壤消化过程。

项目成果

Y.Fujikawa, M.Sugahara, E.Ikeda, M.Fukui: "Analysis of trace actinide elements in soil organic matter -Optimization of sample processing to improve chemical separation of U and Pu"Journal of Radjoanalytical and Nuclear Chemistry. 252. 399-405 (2002)

Y.Fujikawa、M.Sugahara、E.Ikeda、M.Fukui：“土壤有机质中痕量锕系元素的分析 - 优化样品处理以改善 U 和 Pu 的化学分离”Journal of Radjoanalytical and Nuclear Chemistry。

Y.Fujikawa, K.Shizuma, E.Ikeda, T.Baba, M.Fukui, M.Saito, H.Yamanishi, T.Uda: "Uranium and plutonium isotope ratio measurement as a tool for environmental monitoring -Experiences in Osaka, Gifu and Hiroshima, Japan"Journal of Nuclear Science and Technolog

Y.Fujikawa、K.Shizuma、E.Ikeda、T.Baba、M.Fukui、M.Saito、H.Yamanishi、T.Uda：“铀和钚同位素比测量作为环境监测的工具 - 大阪的经验，

Y.Fujikawa, K.Shizuma, S.Endo, M.Fukui: "Anomalous ^<235>U/^<238>U Ratio and Metal Elements Detected in the Black Rain from the Hiroshima A-bomb"Health Physics. 84. 155-162 (2003)

Y.Fujikawa、K.Shizuma、S.Endo、M.Fukui：“广岛原子弹黑雨中检测到的异常 ^<235>U/^<238>U 比率和金属元素”健康物理学。

Y.Fujikawa, K.Shizuma, E.Ikeda, T.Baba, M.Fukui, M.Saito, H.Yamanishi, T.Uda: "Uranium and plutonium isotope ratio measurements as a tool for environmental monitoring-Experiences in Osaka, Gifu and Hiroshima, Japan"Journal of Nuclear Science and Technolog

Y.Fujikawa、K.Shizuma、E.Ikeda、T.Baba、M.Fukui、M.Saito、H.Yamanishi、T.Uda：“铀和钚同位素比测量作为环境监测的工具 - 大阪的经验，

藤川陽子, 静間清, 遠藤暁, 池田恵美: "広島原爆の「黒い雨」中の異常なウラン同位体比等の検出"環境衛生工学研究. 16. 184-189 (2002)

藤川洋子、静间清、远藤彰、池田惠美：“广岛原子弹“黑雨”中铀同位素比率异常的检测”《环境卫生工程研究》16. 184-189（2002）。