@misc{oai:repo.qst.go.jp:00069803,
 author = {Zhang, Yongsan and Zheng, Jian and Yamada, Masatoshi and Wu, Fengchang and Igarashi, Yasuto and Hirose, Katsumi and 張 永三 and 鄭 建 and 山田 正俊},
 month = {Jul},
 note = {Since there is no reference material for fallout radioactivity monitoring, prepare such a reference material is necessary for quality control of fallout radionuclides analysis for atmospheric environmental studies. In this work, we report the characterization of Pu activity and its isotopic composition in a fallout reference material prepared by Meteorological Research Institute (MRI), Japan, which was collected at 14 stations throughout Japan in 1963-1979, with reference values of 137Cs, 90Sr and 239+240Pu activities. We analyzed the activities of 239+240Pu and 241Pu, and the atom ratios of 240Pu/239Pu and 241Pu/239Pu using an isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The 239+240Pu activities in this fallout material using acid leaching and total digestion were 6.56 +/- 0.10 mBq/g and 6.79 +/- 0.08 mBq/g, respectively. Atom ratios of 240Pu/239Pu were 0.1915 +/- 0.0015 and 0.1922 +/- 0.0022, respectively. Both 240Pu/239Pu and 241Pu/239Pu atom ratios were slightly higher than those of global fallout, which could be attributed to the deposition of fallout radionuclides resulted from the Chinese nuclear weapons tests conducted in the 1970s. The dominant host phases of 239+240Pu were found to be organic matter-sulfides (70 %) with a relative high 240Pu/239Pu atom ratio, and Fe-Mn oxides (19 %) using a sequential extraction method., The Fifth International Symposium on Radiation Safety and Detection Technology (ISORD-5)},
 title = {Characterization of Pu concentration and its isotopic composition in a reference fallout material},
 year = {2009}
}