Elemental Analysis and Radioactivity Evaluation of Aerosols Generated During Heating of Simulated Fuel Debris: The URASOL Project in the Framework of Fukushima Daiichi Fuel Debris Removal

In order to safely remove fuel debris from the Fukushima Daiichi Nuclear Power Station (1F), it is necessary to quantitatively evaluate radioactive airborne particulate generated by the cutting of nuclear fuel debris. We fabricated Uranium-bearing simulated fuel debris (SFD) with In/Ex-Vessel compositions and evaluated the physical and chemical properties of aerosols generated by heating the SFDs. Based on these results, we estimated the isotopic composition and radioactivity of aerosols produced when 1F-Unit2 fuel debris is laser cut, which is a typical example of a heating method. Plutonium, mainly ²³⁸Pu, ²³⁹Pu ²⁴¹Am, and ²⁴⁴Cm were found to be the alpha nuclide, and ²⁴¹Pu, ¹³⁷Cs-Ba, and ⁹⁰Sr-Y were found to be the beta nuclide of interest.