9:15 AM - 9:30 AM
[MAG34-02] Investigation of chemical and physical properties of radioactive aerosols sampled from SPM tape filters using multiple synchrotron radiation X-ray analyses
Keywords: Fukushima Daiichi Nuclear Power Plant accident, radioactive material, Synchrotron radiation X-ray analysis, aerosol
All particles sampled from the SPM filters in the present study have similar physical properties: a spherical shape and ~1 μm of diameter. Based on 134Cs/137Cs ratios (~1.0) of individual particles, it is expected these particles were emitted from the reactor No.2 or 3 of the FDNPP. These properties are similar to those of Cs-balls reported in previous studies1,2) except for their sizes (Cs-ball: ~2 μm in diameter). Various heavy elements (Rb, Mo, Sn, Sb, Te, Cs, Ba etc.) possibly derived from FPs were commonly detected from all these particles by the SR-µ-XRF. In addition, it was revealed that some particles contain trace amount of U. While we examined chemical states of four metal elements (Fe, Zn, Mo and Sn) contained in these particles by the SR-μ-XANES, all analytical results indicated that these elements exist as a glass state with high oxidation states in these particle. Results of the SR-μ-XRD also verified that these particles are amorphous materials. Because of these obvious similarities of chemical and physical properties between radioactive particles sampled from the SPM filters collected at the Kanto region and the Cs-balls, we thus concluded that particulate radioactive materials equated with the Cs-ball passed through the Kanto region on March 15th 2011. At the same time, our analytical results demonstrated the U possibly originated from the fuel certainly arrived to the Kanto region just after the accident.
Acknowledgments: We thank to all local governments for allowing us to investigate the SPM filter samples.
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