Vertical distributions of 239+240Pu activity and 240Pu/239Pu atom ratio in sediment core of Lake Chenghai, SW China
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Due to the different 240Pu/239Pu atom ratios from different sources of Pu in the environment, Pu isotopes have been widely used for source identification of radionuclides in sediments. In this work, using sector-field ICP-MS, we investigated Pu inventory and its isotopic composition in a lacustrine sediment core collected in Chenghai Lake, SW China. The 240Pu/239Pu atom ratios in this sediment core ranged from 0.166 to 0.271 with a mean of 0.195±0.021, which was slightly higher than that of global fallout. The 239+240Pu/137Cs activity ratios ranged from 0.0155 to 0.0411, with a mean of 0.0215, and the 239+240Pu inventory was 35.4 MBq/km2; both 239+240Pu/137Cs activity ratio and Pu inventory were close to those values of global fallout at 20–30 °N. Three peaks were observed for both 137Cs and 239+240Pu activities in the examined sediment core; they most probably indicated the maximum deposition of global fallout between 1963 and 1964, the fallout from a series of Chinese nuclear tests during the 1970s, and the deposition of resuspended Pu-bearing particles from the Chernobyl accident. Therefore, the vertical profile of Pu isotopes should provide useful time markers for rapid dating of recent sediments.
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- 13.Z. Q. Yuan, D. S. Wu, R. G. Huang, Z. L. Chen, F. C. Wu, G. J. Wan, Environ. Sci., 14 (1993) 70 (in Chinese).Google Scholar
- 15.UNSCEAR, Sources and Effects of Ionizing Radiation, United Nations Scientific Committee on the Effects of Atomic Radiation Exposures to the Public from Man-made Sources of Radiation, United Nations, New York, 2000.Google Scholar
- 16.E. G. Agudo, IAEA-TECDOC-1028, 1998, p. 117.Google Scholar
- 17.G. J. Wan, W. Z. Lin, R. G. Huang, Z. L. Chen, Chinese Sci. Bull., 36 (1991) 674.Google Scholar
- 18.C. J. Zhang, J. Cao, Y. B. Lei, H. M. Shang, Acta Sedimentologica Sinica, 22 (2004) 494.Google Scholar
- 20.Y. Yamada, K. Yasuike, K. Komura, J. Nucl. Radiochem. Sci., 6 (2005) 135.Google Scholar