Studies on plutonium in terrigenous air-dust

陆源气尘中钚的研究

• 批准号: 09640581
• 负责人: NAKANISHI Takashi
• 金额: $ 2.18万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640581/
• 关键词: air-dust; terrigenous air-dust; Pu-239, 240; Fe; Po-210; Pb-210; ocean flux; 土壌粒子塵; Am-241; Pb-210放射能比; Pu-239

For a study to estimate terrigenous air-dust fluxes to oceanic region by using environmental plutonium as a tracer, Pu-239, 240 and Fe were determined in air-dust samples collected in Kanazawa, Japan through the years from 1993 to 1998. The air-dust samples were collected using a five-stages (particle size : <1.1 μm, 1.1〜2.0 μm, 2.0〜3.3 μm, 3.3〜7.0 μm, 7.0 μm<) Andersen-type high-volume air sampler, and catcher plates and backup filter were replaced monthly ; air-dust collected every 1-8 months was analyzed as one batch.Throughout the above mentioned sampling years and particle sizes, the concentrations of Pu-239, 240 and Fe I n the air-dust samples were in a range from 0.1 to 10 μBq-Pu/mg-dust and from 2 to 30 μg-Fe/mg-dust. The Pu/Fe concentration ratios tend to be high in finer air-dust, suggesting that Pu is adsorbed on the surface of terrigenous air-dust. Through the analyses of Po-210/Pb-210 activity ratios in air-dust samples collected occasionally for a few days using Andersen-type low-volume air sampler, from 9 to 140 days were estimated as the apparent floating time of air-dust (particle size : O.06〜0.13 μm, O.13〜0.22 μm, O.22〜0.33 μm, 0.33〜0.52 μm, 0.52〜0.76 μm, 0.76〜1.3 μm, 1.3〜2.5 μm, 2.5〜3.9 μm, 3.9〜5.7 μm, 5.7〜8.5 μm, 8.5〜12.1 μm).

为研究以环境钚为示踪剂估算陆源大气粉尘向海洋地区的通量，对1993年至1998年在日本金泽采集的大气粉尘样品中的Pu-239、240和Fe进行了测定。空气粉尘采样采用Andersen型五级大流量空气采样器(粒径：1.1μm，1.1~2.0μm，2.0~3.3μm，3.3~7.0μm，7.0μm&lt；)，每月更换捕集板和后备过滤器；每1~8个月采集一次的空气粉尘作为一批进行分析，在上述采样年限和粒度范围内，空气粉尘中Pu-239、240和Fe的浓度范围分别为0.1~10μBq-Pu/mg尘和2~30μg-Fe/mg尘。Pu/Fe浓度比在较细的气尘中趋于较高，说明Pu吸附在陆源气尘的表面。用安徒生型小流量空气采样器对偶尔采集的几天空气粉尘样品中的Po-210/Pb210活度比进行了分析，估算出9~140d为空气粉尘的表观漂浮时间(粒径：0.06~0.13μm，0.13~0.22μm，0.22~0.33μm，0.33~0.52μm，0.52~0.76μm，0.76~1.3μm，1.3~2.5μm，2.5~3.9μm，3 9~5 7μm、5 7~8 5μm、8 5~12 1μm)。

项目成果

M. A. Haque, T. Nakanishi: "Host phase of ィイD1239,240ィエD1Pu and ィイD1241ィエD1Am in deep-sea sediment"J. Radioanal. Nucl. Chem.. 239(3). 565-569 (1999)

M. A. Haque，T. Nakanishi：“深海沉积物中 D1239、240D1Pu 和 D1241D1Am 的宿主相”J. Radioanal Chem. 239(3) (1999)。

M.A.Haque,T.Nakanishi: "Chemical dissolution of total content of fallout plutonium in deep-sea sediment"J.Radional.Nucl.Chem.. 241(3). 575-579 (1999)

M.A.Haque，T.Nakanishi：“深海沉积物中沉降钚总含量的化学溶解”J.Radional.Nucl.Chem.. 241(3)。

Y. Miyamoto: "Interferences in neutron and photon activation analysis"J. Radioanal. Nucl. Chem.. 239(1). 165-175 (1999)

Y. Miyamoto：“中子和光子激活分析中的干扰”J。

Y.Nozaki,M.Yamada,T.Nakanishi,Y.Nagaya,K.Nakamura,K.Shitashima,H.Tsubota: "The distribution of radionuclides and some trace metals in the water columns of the Japan and Bonin trenches" Occanologica Acta. 印刷中.

Y. Nozaki、M. Yamada、T. Nakanishi、Y. Nagaya、K. Nakamura、K. Shitashima、H. Tsubota：“日本和小笠原海沟水柱中放射性核素和一些痕量金属的分布”《海洋学学报》正在打印。

Y. Miyamoto, H. Haba, A. Kajikawa, K. Masumoto, T. Nakanishi, K. Sakamoto: "Interferences in neutron and photon activation analysis"J. Radioanal. Nucl. Chem.. 239(1). 165-175 (1999)

Y. Miyamoto、H. Haba、A. Kajikawa、K. Masumoto、T. Nakanishi、K. Sakamoto：“中子和光子活化分析中的干扰”J.